REAL MAN TRUCKWORKS & SURVIVAL

VEHICLES, CAMPERS, and BOATS => Build Threads => Topic started by: KensAuto on December 07, 2019, 07:25:49 PM

Title: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 07, 2019, 07:25:49 PM
This is the one vehicle that I'm attached to. My '73 that was purchased on payments in highschool, owned by my shop teacher. We painted it in the body shop, with free paint, school bus yellow... just before I acquired it.

About 14 years ago the original body, abused from 4 wheeling and mudding, was replaced by pieces of a '78, '82, '87, etc. and painted to match my 2000 half ton. The power plant is currently a 66 Pontiac 400, which replaced the worn out 71 Firebird 400, which replaced the blown (up) 350. She also has a 4sp backed up with a 205 transfer case.

(https://uploads.tapatalk-cdn.com/20191208/60c4a7a11f6fe1155b046e7f1ccbacf2.jpg)(https://uploads.tapatalk-cdn.com/20191208/331ff6f3fb264ad1327750e310593300.jpg)(https://uploads.tapatalk-cdn.com/20191208/dfa8faba33ab95fa89bb5579ebb2ca70.jpg)(https://uploads.tapatalk-cdn.com/20191208/235c46d6303bca5150a74b5fd4470111.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 07, 2019, 07:35:59 PM
I wanted to install a diesel when I rebuilt the truck, but didn't have the funds, nor the time. I had built the 2nd Pontiac engine to install in a Tempest so it was an easier solution at the time.
A Duramax was the original dream, just because I'm a GM guy, but just don't want the headache.

She lost the AC compressor a few years ago so I parked it. A couple weeks ago we pulled the fuel tanks out to clean, and shortly after, I came across a great deal on a '86 square body that was already swapped.
.. impeccable timing.

This is that truck. It's a western hauler conversion which probably had a big block. I bought it cheap not knowing if the engine was good, or what year it was. All I knew was that it was 2wd, NV4500, and had a P-pump.
(https://uploads.tapatalk-cdn.com/20191208/6223232db2417023f77a14bdffde4582.jpg)(https://uploads.tapatalk-cdn.com/20191208/f9c2fda309f2c74804a76e9bcb7b0c44.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 07, 2019, 07:43:39 PM
It didn't take long to get it running, and it sounded great. Took it for a drive to check out the transmission and found the 3rd gear synchros toast.
I was so excited about this project that I pulled the engine/trans the next day.

The oil fill tube had unscrewed itself from the timing cover and made one heck of a mess over the years. Can't believe no one noticed. It took me over 4 hours to steam clean the engine, trans, and radiator.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: oklawall on December 07, 2019, 07:54:23 PM
This sounds like this will be fun to watch. By the way I'm a firm believer in that a a clean engine/transmission makes a happy mechanic
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 07, 2019, 08:03:43 PM
Dang pics keep turning around.

The engine ID plate on the front cover says it's a '90, 160 horse motor, so I would assume a certain devious dowel pin probably took out the original housing, and no one saved the original plate. The P-pump numbers show that it's one of the more desirable engines, a '96, 215 horse, manual trans. I'm good with that.

...best part is that I got 2 additional engines with the truck. After running the pump numbers, they are both '95s, with 175hp.(https://uploads.tapatalk-cdn.com/20191208/1af29f52d20c2016805a74542687d77c.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 07, 2019, 08:17:01 PM
First task is to relocate the AC compressor. The old Chevy's had fairly narrow frames up front. In the pics below you can see where they just chopped and folded over the passenger side frame to make room in the 86. I don't want to cut the frame.

(https://uploads.tapatalk-cdn.com/20191208/2bdfc75fb640fe81295b92504012e837.jpg)(https://uploads.tapatalk-cdn.com/20191208/d1ef55feb92b8868615ceb06a24a4b01.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 07, 2019, 08:26:01 PM
A common option is to use pieces from a medium duty truck. They have high mount compressors, but I don't want to spend the time and money trying to source all the correct parts, which leads to a third option...
...aftermarket relocation brackets. These seem to range in the $600-1200 range.
Not unless I'm forced to. Trying to keep this cheap, being my slow season at the shop.
Here's where I'm at right now. I layed the alternator over on it's side. I modified (narrowed) the upper alternator mount (thermostat housing) to the same size as a Sanden style compressor, (minus 1/4") that I had in the shed.
Then made a 1/4" bracket going from the main Alt. bolt up to the main compressor bolt. I welded a side brace that bolts to the oil cooler.

 Side note: If this fails I guess you all will be witnesses. Lol

Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 07, 2019, 08:31:59 PM
Just so happened that the original upper bracket for the alternator fit the other set of lower ears on the compressor, by trimming the welded on nut by 1/8". Just need to drill them to 3/8" to match the compressor ears.

This is as it stands right now.

Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on December 07, 2019, 08:39:19 PM
How the body of the western hauler?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 07, 2019, 09:32:31 PM
Drivers side doors are pretty beat up. Rest not too bad. Thinking about using the bed on mine. I think dual swampers look pretty good.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: wilsonphil on December 07, 2019, 09:57:41 PM
Ken its out, if it were me I would pull the cover and check the timing case bolts and KDP AND pull the pan and see what one of the rod bearings look like.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 07, 2019, 10:48:11 PM
We're tracking the same. Already got gaskets, kdp fix, and beige paint. As soon as the AC is sorted, I'm going to reseal it.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: wilsonphil on December 08, 2019, 12:36:39 PM
dont forget about the gearcase bolts, id pull everyone you can get too and locktight them
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 08, 2019, 01:38:13 PM
dont forget about the gearcase bolts, id pull everyone you can get too and locktight them
Will do boss.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 08, 2019, 01:42:16 PM
So today I'm just trying to finish this bracket while also trying to keep warpage down. This cross piece should finish it off in the strength department.(https://uploads.tapatalk-cdn.com/20191208/d3752aa9bcd0ca82c73628e83fc859fe.jpg)(https://uploads.tapatalk-cdn.com/20191208/b2157fb1ba3a607e071e80a9626c7900.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 08, 2019, 01:48:30 PM
Now for the tensioner. I thought it would be easier keeping it Dodge so I went through the catalog and found a compact unit for an early V-10. I need to space it out 7/8" from the new bracket.(https://uploads.tapatalk-cdn.com/20191208/234393a816d0d731e31da6069887f982.jpg)(https://uploads.tapatalk-cdn.com/20191208/26f03a84fb48579e7ac3ddd83d790d72.jpg)(https://uploads.tapatalk-cdn.com/20191208/af1ddc612b0e033aeee8d5cbd43f94ed.jpg)(https://uploads.tapatalk-cdn.com/20191208/6500dbc710b0787b4e7b261a888699b8.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on December 08, 2019, 09:29:23 PM
Sweet so far, another fluid change!

 :likebutton:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on December 08, 2019, 10:10:35 PM
Nah. This one will get done


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 09, 2019, 11:40:12 AM
Nah. This one will get done


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Ouch.

.. not if I keep making mistakes like putting the tensioner bolt in the middle of the belt routing. :Facepalm
Looking for a specific allen bolt now.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: wilsonphil on December 09, 2019, 04:22:10 PM
Don’t forget the motor is all metric
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 09, 2019, 10:43:59 PM
Ended up using an allen bolt, with the head turned down on the lathe, to mount the tensioner. Also added a wider pulley to make proper contact with the 8 rib belt.
After lacing the belt on, in a completely different pattern than the original, I realized that the alternator didn't have enough contact on the pulley.
I added an idler pulley where the original tensioner once resided. Time will tell if it's enough.

The new belt is exactly 4 inches longer and not hard to find.(https://uploads.tapatalk-cdn.com/20191210/9d9e87759d63e19976c7d94615b10e6b.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 09, 2019, 10:53:35 PM
While I was working on the front I decided to install a top dead center pointer. I used the timing pin to locate TDC then cut a groove in the balancer. Then made a pointer that bolts to the cover and case. To those that aren't aware, the Cummins balancer can bolt on in 4 different positions, *90 apart. I'll have to keep it in the right location for the pointer to work.

I made the plate large enough to remount the crank position sensor if I ever desire to run a tach. (Took the sensor off when rerouting the belt)(https://uploads.tapatalk-cdn.com/20191210/e15756d1ad0f50a5f61bcf7edd027ccd.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on December 10, 2019, 12:00:49 AM
Nice mod vs buying all those parts.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on December 10, 2019, 09:23:45 AM
The inventiveness of all youz is wonderful to see!

Keep learnin the rest of us PP
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 10, 2019, 08:40:57 PM
Got tired of working on the engine today, especially since it was cold outside and there isn't room in my tiny shop for it, so I started on converting the NV4500 2wd trans to a 4wd.

First, I layed out the necessary tools and gasket kit...(https://uploads.tapatalk-cdn.com/20191211/5d161bc0c0754b496c1375d2e129eaf8.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 10, 2019, 08:58:24 PM
Just kidding of course^^^ (forgot the pipe wrench)

Then tore it down.
Disclaimer: There's basically 2 mechanical type jobs that I usually won't do for customers. Rebuild transmissions, or rear differentials. So this should be interesting.

I received a rebuilt kit that includes an updated 4wd main shaft and 5th gear, with a new locking nut to hold it on. This is the main failure point on the 4500...the nut comes loose causing a mess. The updated shaft has full length splines for 5th, where as the stock one is only splined 1/3 of the way through the gear.(https://uploads.tapatalk-cdn.com/20191211/393b16d972620a576c553c8b4580da78.jpg)(https://uploads.tapatalk-cdn.com/20191211/a9ca69e4a27c383a509094dd8f9f2047.jpg)(https://uploads.tapatalk-cdn.com/20191211/ee870b3836c2fa3ba9e9c4b4b8261846.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 10, 2019, 09:05:59 PM
And that was it for today. Found some bad hard parts (didn't come in the kit) which would make it extremely difficult to shift into 3rd gear, which is funny because when I drove it around the yard before teardown it wouldn't shift into 3rd. Go figure.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: EL TATE on December 11, 2019, 12:48:41 PM
Got tired of working on the engine today, especially since it was cold outside and there isn't room in my tiny shop for it, so I started on converting the NV4500 2wd trans to a 4wd.

First, I layed out the necessary tools and gasket kit...(https://uploads.tapatalk-cdn.com/20191211/5d161bc0c0754b496c1375d2e129eaf8.jpg)

cold like what, low 70's, lol?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 11, 2019, 12:59:51 PM
40s !!!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on December 11, 2019, 01:49:01 PM
Wow. They probably shut down the town. It was 42 here this morning.


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on December 11, 2019, 03:51:09 PM
Colder here in Kali,,,,,,,,,,,
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: cruizng on December 11, 2019, 04:31:21 PM
Well I'm sure Sam will chime in from Way up North but it was minus 14 this morning with a wind chill of minus 28. Again.. balmy for Sam.. :)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 13, 2019, 07:05:48 AM
While I was working on the front I decided to install a top dead center pointer. I used the timing pin to locate TDC then cut a groove in the balancer. Then made a pointer that bolts to the cover and case. To those that aren't aware, the Cummins balancer can bolt on in 4 different positions, *90 apart. I'll have to keep it in the right location for the pointer to work.

I made the plate large enough to remount the crank position sensor if I ever desire to run a tach. (Took the sensor off when rerouting the belt)(https://uploads.tapatalk-cdn.com/20191210/e15756d1ad0f50a5f61bcf7edd027ccd.jpg)

i ran an autometer diesel specific tach that reads off the alternator and can be tuned depending on pulley size. did it on the kaiser as well as turners rig.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 13, 2019, 09:15:15 AM
I was curious how his tach worked, just forgot to ask. Good info.

Finished the transmission yesterday. Had to make a socket for the 5th gear nut. Torque is supposed to be 275ft lbs...using a large prybar, I turned it 'til my shoulder clicked. Should be close.

Snagged a cast iron 4wd tailhousing off of eBay. Now I need to spend some coin on an expensive adapter to hook up the 205.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on December 13, 2019, 10:46:53 AM
275?  Four foot cheater bar with your feet off the ground??


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: EL TATE on December 13, 2019, 12:04:01 PM
and a jack handle
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on December 13, 2019, 01:04:17 PM
Tack weld the nut in place and forget it.....
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 13, 2019, 07:01:27 PM
Thanks Shawn for being so helpful. I knew I could count on you buddy.

Started resealing the engine today. Took the pan off first to check out the bearings, only to make WilsonPhil happy, per his request. (It passed his critiquing).
Also looks like someone balanced this motor. I'll probably pull the head to see if anything else was modded.(https://uploads.tapatalk-cdn.com/20191214/4e8059f90f2c2e155a68df344be59b24.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 13, 2019, 07:07:54 PM
Also received the new blurple mount brackets. The old ones were made to fit some old Ford 390 pancake style mounts...not very strong at all.
The new ones fit regular gm mounts.
My employee had some poly ones that he donated to the cause.

First pics are the Ford ones.(https://uploads.tapatalk-cdn.com/20191214/30269692c352ead5d9ce99c92a0a23b1.jpg)(https://uploads.tapatalk-cdn.com/20191214/de575cc6176e4dc93524e4c531fb393f.jpg)(https://uploads.tapatalk-cdn.com/20191214/75cf2c25dd46fb0cdf452699d31b132f.jpg)(https://uploads.tapatalk-cdn.com/20191214/036ce8c5b81f817810fd35173cf7aa26.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on December 13, 2019, 07:37:33 PM
Thanks Shawn for being so helpful. I knew I could count on you buddy.

Started resealing the engine today. Took the pan off first to check out the bearings, only to make WilsonPhil happy, per his request. (It passed his critiquing).
Also looks like someone balanced this motor. I'll probably pull the head to see if anything else was modded.(https://uploads.tapatalk-cdn.com/20191214/4e8059f90f2c2e155a68df344be59b24.jpg)

Well, you know us welding types.....
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 15, 2019, 09:01:16 PM
what kind of 205 do you have?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 15, 2019, 09:03:22 PM
.. i have the 205 you need. but it would maybe be more expensive’r than what you can get from precision. hahah
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 15, 2019, 09:03:52 PM
From 1973, pass drop, 10 spline. Figure 8... guess I have to mil the case for the larger 29 spline female.

What do you have?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 15, 2019, 09:06:12 PM
From 1973, pass drop, 10 spline.

you’re going to have to big bore swap the 10 spline over to 29, yes?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 15, 2019, 09:06:45 PM
i have a getrag 29 spline 205 from a first gen  :rolleyes:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 15, 2019, 09:18:42 PM
29 spline 205 with adapter

(https://i.imgur.com/Ek9WYDW.jpg)

and this was a 27 spline 80mm small bore case.

now, it’s going to be a 31 spline 90 mm big bore case for a 203/205 doubler.

(https://i.imgur.com/TtkDIFy.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 15, 2019, 09:37:41 PM
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 15, 2019, 09:40:58 PM


and you’ll need a 29 spline male.. then a 29 spline female/female (if you go the route i’m thinking you are. if you have a way to do it with a 29 spline female input for the 205.. please disregard previous statement lol)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 15, 2019, 10:29:46 PM
The kit I'm looking at is 29 female that hooks up to the new 29 output on the nv4500. Over 5 bills.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on December 15, 2019, 10:59:48 PM
Can’t you source a 32 spline output from another nv4500 and use a ford np205 32 spline input?

I might know someone who has both btw......  :tongue:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 15, 2019, 11:07:46 PM
I have access to 2 Ford 32s, but driver's drop. No bueno.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on December 15, 2019, 11:23:17 PM
I have access to 2 Ford 32s, but driver's drop. No bueno.

Pull the input and bore the gm case to fit
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: America.Mike on December 16, 2019, 12:07:46 AM
   I rebuilt the dodge nv4500 case and installed a Chevy 32 spline mainshaft.


  With my transfer case and doubler I bored the NP205 case  for a 90mm big bearing. Im  installing a ford 31 spline input a  cut resplined and heat treated  mainshaft for the NP203 and a 32spline input.


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Title: 12v Cummins Swap/'73 GMC 2500
Post by: America.Mike on December 16, 2019, 12:09:46 AM
Trucks going to be sweet when done.


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 16, 2019, 07:21:39 AM
I have access to 2 Ford 32s, but driver's drop. No bueno.

might want to recount.. i think they’re 31 spline and short input. you’d need a 32 spline long from a chevy behind a TH400 or 4L80 i believe.

which kit are you thinking of using?

that gray case i have started out as a small bore. couple hours at the machine shop and now it’s a big bore lol
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 16, 2019, 08:21:36 AM
You guys are making my head hurt.
I think you're right Seth, 31 spline now that I think about it.
I like the doubler idea, but this truck won't get used much. She's semi retired to a much easier life now. .. only need 4wd to pull Don out of the mulch beds when he comes to visit.
(https://uploads.tapatalk-cdn.com/20191216/e7f9656fb9fffc31dd869959314a79bd.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 16, 2019, 08:28:22 AM
that’s a pretty sweet kit actually. shortens up drive train length some (not that you need it in SCLB square body..) and reduces pieces used.

if you do run across a 29 spline dodge case, they bolt right up to the 4500. did it for the kaiser. where exactly are you located? out by turner?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 16, 2019, 08:36:31 AM
I'm thinking with that kit I should be able to reuse the stock Chevy single stick without hitting my bench seat. As it is, looks like the nv4500 stick is going to move back about 3-4 inches farther towards the seat. I don't really want to have to use a remote twin stick at this time.... also don't want bucket seats.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 16, 2019, 09:54:47 AM
I'm thinking with that kit I should be able to reuse the stock Chevy single stick without hitting my bench seat. As it is, looks like the nv4500 stick is going to move back about 3-4 inches farther towards the seat. I don't really want to have to use a remote twin stick at this time.... also don't want bucket seats.

well.. if you get to that point, i have a set of JB fab shifter and some short cables if you need. can sell cheap ish (not MSRP..  :rolleyes: ) thanks to another member on here..
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 16, 2019, 10:25:44 AM
I'm thinking with that kit I should be able to reuse the stock Chevy single stick without hitting my bench seat. As it is, looks like the nv4500 stick is going to move back about 3-4 inches farther towards the seat. I don't really want to have to use a remote twin stick at this time.... also don't want bucket seats.

and if it’s any confirmation.. when we put the 4500 in the kaiser it pushed the shifter back (from original 4 speed) about 4” as well. just for comparison.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 16, 2019, 01:58:01 PM
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on December 16, 2019, 06:40:46 PM
GM and Dodge shifter angles are different, One is more straight up and down than the other fyi.....
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on December 17, 2019, 08:19:18 AM
GM and Dodge shifter angles are different, One is more straight up and down than the other fyi.....

is this for 205s or 4500s?

i can get an angle from a ‘99 dodge NV4500 and report back
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 17, 2019, 08:29:45 AM
While you guys sort out the shifter angles....

Next up was resealing the t-cover. Good timing on my part, no pun intended. The infamous dowel pin had started it's exodus from the block, and the 4 rear housing screws were fairly loose.
The black piece blocks the dowel from coming out, and the new allen bolt is too long to unscrew by itself, without hitting the outer cover.(https://uploads.tapatalk-cdn.com/20191217/7e8b9d3d1d92cd8d34eddf9c98a24578.jpg)(https://uploads.tapatalk-cdn.com/20191217/91c00e2993005cfe15caafb8f161efba.jpg)(https://uploads.tapatalk-cdn.com/20191217/57a4be595203166021250c6f8d1ccad0.jpg)(https://uploads.tapatalk-cdn.com/20191217/1c453fc64dff4dc7316a24b7d174c080.jpg)(https://uploads.tapatalk-cdn.com/20191217/19ef2384baac8b3fc88e91e03f37d51e.jpg)(https://uploads.tapatalk-cdn.com/20191217/1b1f765a776708a49106355daf4fcdb8.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: wilsonphil on December 17, 2019, 10:59:30 AM
I have seen the bolts for the gear case destroy more Cummins than the Dow pin, glad you got to them now, locktite is your friend.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on December 17, 2019, 02:54:28 PM
GM and Dodge shifter angles are different, One is more straight up and down than the other fyi.....

is this for 205s or 4500s?

i can get an angle from a ‘99 dodge NV4500 and report back

4500's, I have GM if you need but I think the base of the handle could be warmed up and tweaked slightly....
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 26, 2019, 09:48:25 PM
Finally did an initial mock-up on the engine.
(https://uploads.tapatalk-cdn.com/20191227/f8202d2cac87fbb08b5d879bb2828c19.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 26, 2019, 09:53:56 PM
Then pulled it back out to start cutting the sway bar crossmember, and relocating the brake proportioning valve, to clear the harmonic balancer.
I basically cut out 2" vertical, then welded a 1" strip back in as a lip, curved to match the balancer.(https://uploads.tapatalk-cdn.com/20191227/3637e8822340d7cb3178ef640be1fb5e.jpg)(https://uploads.tapatalk-cdn.com/20191227/7fb1eb11004694165b697d15908fb6ff.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 26, 2019, 09:58:32 PM
...then added some gussets to the front side as well as relocating the valve from the rear to the front. Extended the brake lines and called it good enough.(https://uploads.tapatalk-cdn.com/20191227/5243c3a22816c4745575f509091e0893.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on December 26, 2019, 10:10:07 PM
Nice work, seems to be a common thing for the swap.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Bigdave_185 on December 26, 2019, 10:53:10 PM
Good enough from my house!


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on December 27, 2019, 07:33:26 AM
Looking good Ken. 


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 28, 2019, 09:26:17 PM
Built a stout crossmember today. The motor mounts get welded to it, then I'll box everything in once the engine comes back out.
I used some 3/16" walled 2x5 rec tube.
It was cut with a newly acquired band saw that was in pretty bad shape. One of the things I had to do was mill out one of the big pulleys and install brass bushings.
Pics before and after:

(https://uploads.tapatalk-cdn.com/20191229/c8c71b9a80e0121e7bae2094c5c97ab1.jpg)(https://uploads.tapatalk-cdn.com/20191229/ed5b51dd104894a2f1d2034d20fc2e14.jpg)(https://uploads.tapatalk-cdn.com/20191229/e919254452ea19d81278f4f9a8e86704.jpg)(https://uploads.tapatalk-cdn.com/20191229/d003a985362ec6f6857b236c28118dcb.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 28, 2019, 09:27:58 PM
..the crossmember tacked in place(https://uploads.tapatalk-cdn.com/20191229/6cdfc65ede4c6856eb2662e4c5425395.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on December 28, 2019, 09:46:02 PM
Ken, normally you can buy saw parts online pretty reasonable and quick. I used to buy Kalamazoo saw gears all the time, just for reference.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 28, 2019, 09:51:39 PM
One of the things I was worried about was the turbo contacting the evaporator case. The case in the donor truck was caved in and burnt...so...
I found a used 24v manifold off a medium truck that has a rear turbo mount, so I mocked it up today.

First pic is of the donor truck, before I pulled the engine.
Other pics are of the 24v manifold.(https://uploads.tapatalk-cdn.com/20191229/e73b2a14828efd95ee1683b99163ad8b.jpg)(https://uploads.tapatalk-cdn.com/20191229/e8fe06530017cd00a6ee0537636f4453.jpg)(https://uploads.tapatalk-cdn.com/20191229/8aa365b2edb23eb60c6f168fae4e5ae2.jpg)(https://uploads.tapatalk-cdn.com/20191229/949f7d1e3b5b84c606857b3a2f8c0450.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 28, 2019, 09:54:59 PM
Then for the heck of it, I stuck the original manifold back on, and it has plenty of clearance. Weird, but makes life easier.(https://uploads.tapatalk-cdn.com/20191229/a35a4e8282f5e8f7191f787f3b3020b0.jpg)(https://uploads.tapatalk-cdn.com/20191229/2dded64a159dc5f6a74bd7a0f8d57686.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Bigdave_185 on December 28, 2019, 10:27:07 PM
What improvements are there for a 24v vs the 12v besides the turbo location ?

Looks like it has a good bit more mass to it


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 28, 2019, 10:54:31 PM
I don't think it would add any noticable performance. The 12v has rectangular exhaust ports and the 24v has round ones, so you actually have to grind them to match the 12v head. One less thing I have to do now if I keep the original.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on December 29, 2019, 07:39:08 AM
What are you going to use for heat shielding?  Wrap the turbo and shield the evap?


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on December 29, 2019, 11:32:15 AM
I'll throw a blanket on the turbo, wrap the downpipe, and call it a day.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on December 29, 2019, 01:30:48 PM
Nice progress.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on December 30, 2019, 02:03:12 PM
looking good

Fast build
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 08, 2020, 08:43:05 PM
looking good

Fast build
Thank you kindly.

I got distracted with a couple busy weeks at work, which is strange for this time of year, but spent a few minutes on the project.
First, I pulled the engine back out after some measurements. I had originally decided not to replace the side cover gasket because I didn't want to pull the injection pump. This caused me many restless nights.
...so the pump was removed and the side cover gasket replaced:(https://uploads.tapatalk-cdn.com/20200109/7b800a2b2abd89a8127616c467e5ec0c.jpg)(https://uploads.tapatalk-cdn.com/20200109/177c123d0f0529f400c5b0ca800ed592.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 08, 2020, 08:52:36 PM
Then went against my original plan to leave this engine at the stock 215hp.

First was the upgraded governor springs. This takes the stock rev limit from about 2800 to 4000. Thanks to the internet, this was painless.
You basically remove a 22mm plug in the governor housing, turn the pump to access one set of springs, then rotate the pump shaft 180* to access the second set, and not drop anything inside.(https://uploads.tapatalk-cdn.com/20200109/0018e067bf70c4d477b1ec55357e5eb6.jpg)(https://uploads.tapatalk-cdn.com/20200109/2f7fca3e2929ba8b5d921fc7f4251f8b.jpg)(https://uploads.tapatalk-cdn.com/20200109/728a37d0cb191fb50de436593fb780e5.jpg)(https://uploads.tapatalk-cdn.com/20200109/7bbff92a1606013ff31b8882ec349e1f.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 08, 2020, 08:56:31 PM
The only pieces you reuse are the outer large springs, the outer spring cup, and the slotted nut. Shims and other springs are left out.(https://uploads.tapatalk-cdn.com/20200109/6d3089bf55c0fcee147d5b971edd6515.jpg)(https://uploads.tapatalk-cdn.com/20200109/94a0318d055f61ac3dbfd8aefff2d726.jpg)(https://uploads.tapatalk-cdn.com/20200109/2b4ee2f8dd2ae527e867f52c089b26d2.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 08, 2020, 09:04:13 PM
Then the AFC housing was removed to access and replace the fuel plate. I went with a conservative choice, a #10.

I'm not going into crazy detail on these mods since there's plenty of videos on the net already, and it technically has little to do with the original purpose of this thread.(https://uploads.tapatalk-cdn.com/20200109/9937ee3718f6f98f8b9ddb462ab5ff2d.jpg)(https://uploads.tapatalk-cdn.com/20200109/67382755c334bbc5f709deca9631f7cc.jpg)(https://uploads.tapatalk-cdn.com/20200109/cb983a6c919343b0b02f18282a0d224c.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 08, 2020, 09:07:33 PM
The old plate for comparison:(https://uploads.tapatalk-cdn.com/20200109/03dbd145454ea6a45c1ccc676d59cc9b.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 08, 2020, 10:22:11 PM
If its not broke, don't fix it has no place in these forums.

Upgrade, then upgrade some more!

 :likebutton:

Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 10, 2020, 10:33:36 PM
The engine is finally ready to install. I had purchased a quart of Cummins beige but I've been told that I have a touch of OCD. If it's black, it makes it harder to see leaks. A normal person would say that is a bad thing, but after turning wrenches for a few years, my thoughts are if you can't see it, it must not be happening.
I did Cerakote the manifold and turbo.

Next up, boxing the frame.(https://uploads.tapatalk-cdn.com/20200111/7bfcdf5635d5a3c17a044e027f538031.jpg)(https://uploads.tapatalk-cdn.com/20200111/b958dd92ac2e39f98a0a22bf71db669d.jpg)(https://uploads.tapatalk-cdn.com/20200111/4efceb96d7af1f514d37f3fa0ab4e2d7.jpg)(https://uploads.tapatalk-cdn.com/20200111/7a62b1a9067def7fe10163d911d55831.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 11, 2020, 07:43:28 AM
I like it Ken  :likebutton:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on January 11, 2020, 08:41:44 AM
Nice!


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: cruizng on January 11, 2020, 02:04:21 PM
Great progress. Next!


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on January 11, 2020, 08:27:21 PM
does that thing run yet?? that’s all anyone here really cares about anyway. hahah
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 11, 2020, 10:45:00 PM
does that thing run yet?? that’s all anyone here really cares about anyway. hahah
I'm sure it's capable of running again, but not capable of driving!

Today I cut out the hardest pieces to start boxing the frame. Anyone that's ever worked on an old truck, especially a GM, knows how uneven the stamped frames can be. In this case, the lower part of the c-channel is almost an inch wider than the upper. ..and the left rail doesn't match the right side, so I can't use the same pattern for both sides.(https://uploads.tapatalk-cdn.com/20200112/dd01b84f515846c572521c98e7434378.jpg)(https://uploads.tapatalk-cdn.com/20200112/d2a0f2efad172ea9308bb2e069141669.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 11, 2020, 10:57:58 PM
Ken, are you checking tolerances on that motor before installation? As I’m
Doing research I’m trying to plan for my own upcoming process including building a stand for it to facilitate all of that.

Edit: sorry after looking back I now see Phil gave it two thumbs up so you must have checked something.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 12, 2020, 12:00:05 AM
Bearings were great, but what I didn't show was the scoring in the cylinders. Looks like someone ran it without an air cleaner for a while. Didn't have much blow-by, so I'm gonna run it.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 12, 2020, 12:07:24 AM
Bearings were great, but what I didn't show was the scoring in the cylinders. Looks like someone ran it without an air cleaner for a while. Didn't have much blow-by, so I'm gonna run it.

 :likebutton:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on January 12, 2020, 08:16:26 AM
Bearings were great, but what I didn't show was the scoring in the cylinders. Looks like someone ran it without an air cleaner for a while. Didn't have much blow-by, so I'm gonna run it.

 :likebutton:

if she’s passes a compression test, i’d say just put some fuel to it and bump the starter and let it ride.

Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 12, 2020, 04:23:23 PM
Looks to good to run, then you don't see leaks either.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: America.Mike on January 12, 2020, 04:41:20 PM
Looking good man! If compression is good run it!


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 12, 2020, 09:00:52 PM
Looking good man! If compression is good run it!


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Thank you sir.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 13, 2020, 01:37:43 PM
Got some pieces welded in.
Yeah I know, the guy that did the welding gets worse with every passing year.(https://uploads.tapatalk-cdn.com/20200113/6b80d7a8e0cb227b758553d17697a518.jpg)(https://uploads.tapatalk-cdn.com/20200113/533e339bbff918225bbeb788c1645313.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 13, 2020, 02:23:10 PM
You going to box the whole frame? Nice while you have it apart.

I would address the steering box now while its open. My 77 was so bad I cut the whole area out then welded solid spacers from the box to inside the frame.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 13, 2020, 09:36:30 PM
Welding isn’t terrible Ken, it appears to be getting good penetration which is most important.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 14, 2020, 12:13:44 AM
You going to box the whole frame? Nice while you have it apart.

I would address the steering box now while its open. My 77 was so bad I cut the whole area out then welded solid spacers from the box to inside the frame.
Weird that mine never cracked there considering what this truck has been through. Gonna box it rearward to the spring hangers. Probably weld a plate on the outside of the frame for the gearbox... would be easier.

Thanks Shawn. Even with a cheater lens I can barely see what I'm welding nowadays.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 14, 2020, 08:12:23 AM
Ken, my neighbor Chuck is in his 69’s and builds hot rods (for himself, been in all the magazines, big sheet metal guy) and is now having cataracts lasered. He’s been using two sets of cheater lenses inside his hood. So I get it....
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 18, 2020, 02:49:52 PM
Finished plating the frame. Added extra to the sides of the mount pedestals, then slotted the holes for more mount adjustability. I know, boring, but necessary tasks.
Next up, I need to swap clutch pedal assemblies and make a place for a hydraulic master cylinder before reinstalling the engine.(https://uploads.tapatalk-cdn.com/20200118/dadd0b988325ad97926e14c27c5bdec1.jpg)(https://uploads.tapatalk-cdn.com/20200118/7d83c7fb545b169b39148da6e791747a.jpg)(https://uploads.tapatalk-cdn.com/20200118/d8a5bce826ffdd94158059173b0d92f7.jpg)(https://uploads.tapatalk-cdn.com/20200118/ed4e3ba0bda2651ad670ab48e571b2b2.jpg)(https://uploads.tapatalk-cdn.com/20200118/b725951fe3a06631ecf43a97fbfa8781.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 18, 2020, 02:53:12 PM
And carried the plate to beyond the rear hangers...(https://uploads.tapatalk-cdn.com/20200118/9e607e6d262e1c90677598f080465cf7.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 18, 2020, 03:16:25 PM
I was going to suggest looking at or replacing the rear spring hangers. All I have removed were wore all the way to the bushing and cutting into it.

You are doing it about like I did my 77. Leaving the cab on you can still get about 99% of it.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 18, 2020, 04:33:54 PM
JR, I've rebuilt this truck twice and spring bushings were done both times...and they're bad again!

I'm putting a D60 in after it's back to being driveable. I bought it about 12 years ago to put in this truck so another year won't matter. I'll have to add some lift to the front anyways.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 18, 2020, 06:17:34 PM
Ken when you do that front you should look at DIY B52’s and re spring the front end.....
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 18, 2020, 06:53:08 PM
Went with the 4x4diy hangers on mine, poly bushings and greaseable.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 18, 2020, 08:55:36 PM
Ken when you do that front you should look at DIY B52’s and re spring the front end.....
Diy b52s? WTH is that? You can build your own bomber? Interesting but I think you posted in the wrong thread. This is a pickup build. ,
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 18, 2020, 08:59:33 PM
https://diy4x.com/product.php?productid=17715
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 18, 2020, 09:12:50 PM
Interesting. Is that what Don put on his Dodge ?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 18, 2020, 11:09:55 PM
I don’t believe so, someone else builds the dodge stuff
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on January 19, 2020, 07:13:12 AM
the duramax swap guy in CA makes a kit for the square bodies that move the shackle hangers to the cab mounts and uses 52” spring. that’s what i’m doing..
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 19, 2020, 03:04:50 PM
website?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 19, 2020, 07:35:57 PM
If, and when I change out the front diff, I'll start a new thread and I'll put this info over there. Leaning towards leaving the leaf springs stock length, but we'll see.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 19, 2020, 09:29:27 PM
It needs an 05 + Superduty 60 front.....
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 19, 2020, 10:42:15 PM
Why? I abused this truck (3 engines and 6 clutches) and never broke the 44. Luckily the front driveline was the weak link.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 20, 2020, 12:21:05 AM
But was it a 1000 lb cummins up top?

Never broke my 44 either, SBC but lots of universals!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 20, 2020, 08:54:00 AM
But was it a 1000 lb cummins up top?

Never broke my 44 either, SBC but lots of universals!
Not much more than a loaded down Pontiac tbh.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 20, 2020, 07:09:12 PM
Well, H in the bed is like what 3 Cummins motors?  :tongue:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Bigdave_185 on January 20, 2020, 10:44:16 PM
Is hot air a power source for vehicles now?


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 20, 2020, 10:48:25 PM
Is hot air a power source for vehicles now?


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Just old dodges......  :popcorn:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: wilsonphil on January 20, 2020, 11:47:54 PM
Dont listen to them Ken, the 440CI engines that are in the Dodge series of truck was only 100lbs lighter than the Cummins.  I beat the snot out of many D44 5lug with a 440 and never had a problem.  Tire weight and size is much more of an issue.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on January 21, 2020, 08:13:36 AM
website?

https://precisionfabricationplus.com/shop?olsPage=products%2F80-91-gm-k-and-v-series-truck-blazer-and-suburban-52-hd-boomerang-shackle-kit&page=3

it moves the front upper shackle hangers (FUSH) back to under the front cab mount which allows your to run 52” (i actually thing he’s building them 53”) which gives you much better/softer ride with the increase length. i also believe he’s pushing the front axle forward 1” to allow for better steering characteristics. only down side is you’d have to take some of the plating off to get to it now..
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 21, 2020, 10:16:34 AM
I have a customer scheduled to do the b52’s and rear shackle flip on his 86 Blazer. New springs and shocks. Trying to build him a hd 44 and 14 bolt locked 8 lug.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 21, 2020, 11:35:51 PM

Working on the clutch hydraulics now.
The donor truck had used the Dodge slave and master. The master was cobbled to the firewall pretty badly so I wanted to do something better.
First I had to swap over the pedal assemblies. Donor truck had hydro pedals, which are different than the'73 mechanical linkage style.

Here they are . Old one on top.
Other pic is of the cobbled twist style adapter for the Dodge master cylinder.

(https://uploads.tapatalk-cdn.com/20200122/cf149e465cd00edbc6aa827fd87dc7d2.jpg)(https://uploads.tapatalk-cdn.com/20200122/26e744c9fc52f0f63336d055a72a2890.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 21, 2020, 11:42:12 PM
The main difference is that the newer style ('85?), has two separate pivot bolts for the clutch and brake, allowing for 2 struts to bolt on the clutch pedal, that extend to, and through the firewall that the master bolts on to.(https://uploads.tapatalk-cdn.com/20200122/7c7fe82ebd109271b005503802cea6cb.jpg)(https://uploads.tapatalk-cdn.com/20200122/e8bc300ccdca982bf3dee732726349c7.jpg)(https://uploads.tapatalk-cdn.com/20200122/656f0a2f89b158233dd5562a1fbeac95.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 21, 2020, 11:45:57 PM
The other thing worth mentioning is that the newer one is set up for a hydroboost. It only has 2 booster studs, instead of 4, like the'73.(https://uploads.tapatalk-cdn.com/20200122/8387114c4b34b1512f343e8200d13322.jpg)(https://uploads.tapatalk-cdn.com/20200122/97aca37bc464078dfb57c500c44cb1eb.jpg)(https://uploads.tapatalk-cdn.com/20200122/30fdd813ba5b64c0c6cb245544f372a2.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 22, 2020, 12:07:20 AM
I wanted to get away from the plastic master, so I spent some time trying to sort that out.

The '85 Chevy version is cast, but only 11/16 bore...but...direct mount and proper rod length and geometry.

The Dodge is 7/8"... not even close. ..no way that smaller bore would work with the Dodge slave. (which is 1" bore )
I'm going to try a cast slave from a 91 Chevy 3500. I'll have to redrill the mounting holes and cut the push rod.
It has a 13/16 bore, for an .85:1 ratio, compared to the Dodge's .875:1 ratio.

With this setup I can get rid of the plastic line and o-ring connections... just hope it works.(https://uploads.tapatalk-cdn.com/20200122/39bccfd7b014d93073c5c951faefa8e1.jpg)(https://uploads.tapatalk-cdn.com/20200122/efe66df591dc5642afd4497b9c653a68.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 22, 2020, 12:12:19 AM
Got a pattern off of the donor firewall, drilled, then mounted the pedal assembly, then the master.
And that's as far as I made it today.(https://uploads.tapatalk-cdn.com/20200122/eb3385d85ea883edc1eedc0fb24a9a0b.jpg)(https://uploads.tapatalk-cdn.com/20200122/0b97fb42b93d67c3a92f81494715a239.jpg)(https://uploads.tapatalk-cdn.com/20200122/9bb4bf340cc85ef4829a47972fc70f61.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 22, 2020, 12:15:53 AM
Have to see what my pedal setup is.

Any aftermarket for the slave, plastic sounds hokey.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 25, 2020, 09:17:01 PM
Ordered some AN adapters to fit the cylinders. 12mm x1.0 threads.
I'll wait till the trans is installed before ordering a braided hose.

(https://uploads.tapatalk-cdn.com/20200126/c52632ec1c8a302db06b8689c7de6e00.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 25, 2020, 09:26:39 PM
One more issue to deal with. In '73 GM vehicles only used a single fuel line...no return system. Most diesels , and gas vehicles after the late 70s, use a supply and a return.
Since I'm replacing the fuel tanks, I ordered newer style senders, with 2 lines.
The original line was on the passenger side. Cummins gets fed from the left side.
I installed new fuel lines:(https://uploads.tapatalk-cdn.com/20200126/a4691ce03a87b018ac40d5db96f640e2.jpg)(https://uploads.tapatalk-cdn.com/20200126/72d84e9bb37adec36a9ecdad9d4c7e8d.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 25, 2020, 09:38:27 PM
The next issue is that the truck has dual tanks. The early square bodys use a simple 3 port switching valve, with one wire. Flip the switch and it sends 12 volts to the valve to switch over to auxillary, or driver's side.
In the late 70s when they went to a return system, they used a similar valve but with 6 ports, so that the return fuel returns to the proper tank... again, a single wire.
That valve is no longer available. The replacements are for the trucks in the 80s, with 6 wires. It can be converted, but I'm too lazy, so I found a used 6 port, single wire to use for now.
^^^^I should really learn to condense my thoughts.

(https://uploads.tapatalk-cdn.com/20200126/a3c4e6d3f0e8eee7df036a00811d4e4d.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 25, 2020, 09:47:33 PM
Now moving on to the cooling stack.
There's no way to make room for an intercooler in a '73 without 'ruining' the radiator support, and using a different grill. ..the only body parts still original, and unmolested. The grill recesses inward, etc. and it's staying.
So, I'm going to run a water to air cooler. Her days of working hard are over so it should be fine.

The grill and hood latch support:(https://uploads.tapatalk-cdn.com/20200126/be1e8f141dee733492631300e5c2e0e7.jpg)(https://uploads.tapatalk-cdn.com/20200126/86b45d8d441be18a7ed281bc1dc0be53.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 25, 2020, 09:52:57 PM
Pics of the donor truck. They were able to cut around the radiator core support channels, then extended the inlet/outlet on the intercooler because they put the cooler on the outside of the condenser. Then they ran an aftermarket grill. ..but the'73 and 80s core supports are way different.(https://uploads.tapatalk-cdn.com/20200126/beaee4ad2154d7a1d709ae6b4542003a.jpg)(https://uploads.tapatalk-cdn.com/20200126/f7f878769e6b22b89f91306f136df7cb.jpg)(https://uploads.tapatalk-cdn.com/20200126/e9c039ed894479901141130fb686bf19.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 25, 2020, 09:57:23 PM
First the factory condenser was tossed in favor of a small one made for r134a.
The intercooler radiator was mounted to that on the outside so I can access the drain.
The assembly was then mounted in the opening.
I have an 1/8" gap between it and the hood latch support... barely fits but good enough.(https://uploads.tapatalk-cdn.com/20200126/533ac5929178e7ca8f2c6ea68848729a.jpg)(https://uploads.tapatalk-cdn.com/20200126/cf30b5e723627c0f5822425e74186991.jpg)(https://uploads.tapatalk-cdn.com/20200126/4abcab6b0490c5ee86e7721b91b838c9.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 26, 2020, 03:32:04 AM
Plus they were diff for 2 or 4 headlights in the 80s, 70s all the same.

What intercooler was that Ken? I got a ford SD that everyone said would fit and it turned right into the uprights.

Mine is the lower 80s hood and already have a aftermarket grill.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on January 26, 2020, 08:07:39 AM
so.. i’ve been doing some reading and thinking (mostly thinking) about how to efficiently run dual tanks on the dmax. well.. not just thinking about dual tanks but also a burb tank behind the rear axle too.

i found a manual 6 port brass valve that would make it fool proof to operate (no wires) and has the return going to the appropriate tank as well. pretty slick design. but i’m not sure i want that. other thought is burb tank. pretty straight forward.  just 33 gal behind the axle.

option #3 i’m tossing around is plumbing the 2 tanks together with a single low ~1” line crossing between the 2.. 

now i know this sounds risky, but a quick glance at the truck the other day shows that the tanks dont hang below the frame.  so. thought: drill a hole in the frame close to the bottom of the channel forward on the tanks. weld bungs into said tanks and have them run across and over DS just behind tcase.

tell me i’m wrong and just need to run a burb tank, not worry about being able to carry a full size spare and need to figure out how to fill it. which would be more functional..?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on January 26, 2020, 08:17:41 AM
 https://www.groco.net/fv-65038 (https://www.groco.net/fv-65038)

here’s that valve. would be perfect sitting under the driver seat of just on the side towards the door.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 26, 2020, 11:47:55 AM
Yeah I didn't mention the manual valve. Not a fan (lots of long rubber hoses to make it work) but definitely an option.

JR, they used the 2nd gen it looks like.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 26, 2020, 12:42:09 PM
I’m with Ken, those hoses are a drawback however I like the mechanical aspect. I may use that on upcoming build actually.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 26, 2020, 01:35:31 PM
Just thought of a different option. The 3 port valves are made in 2 different sizes. GM uses 3/8" ports and Ford, and maybe Dodge, used 5/16", single wire.
Use the 3/8 one for supply and 5/16 for return, wired together. If one quits just make sure the switch is on the main tank and keep trucking.

The main reason I don't want to use the 6 wire modern one is that I used to see issues with them quite often. They have a worm gear motor that drives one way or another. Not only do they quit completely, they can also get stuck in any position. This design is supposed to be better because on the old ones, they stay engaged (solenoid style) when on auxillary. Mine made it 30 years by only using aux. when needed so I have more trust in them.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 26, 2020, 01:47:22 PM
Yeah I didn't mention the manual valve. Not a fan (lots of long rubber hoses to make it work) but definitely an option.

JR, they used the 2nd gen it looks like.

2nd gen Dodge?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 26, 2020, 04:21:18 PM
Yeah
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on January 27, 2020, 10:00:21 AM
Yeah I didn't mention the manual valve. Not a fan (lots of long rubber hoses to make it work) but definitely an option.

JR, they used the 2nd gen it looks like.

i suppose it could be used in conjunction with the factory hard lines and just ‘tapped’ in to with rubber to run to the valve itself. i would imagine some good oil resistant suction line would work alright for the lift pump on the 12 valve. (provided youre staying mechanical and not FASS
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 27, 2020, 10:57:35 AM
That's what I'm doing with the burb. Factory lines, lift near the tank.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 27, 2020, 08:06:16 PM
My factory line ran down the wrong side. Then the new one I ran about 12 years ago was on the same side as well. Lol

Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on January 27, 2020, 08:58:22 PM
My factory line ran down the wrong side. Then the new one I ran about 12 years ago was on the same side as well. Lol

pretty sure the ones on my crew are on the driver side. just get some of those
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on January 28, 2020, 10:32:39 AM
^^^ That's a big thumbs up!

Had to purchase additional storage space just to keep it on the thread!

Wow!

;-)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on January 28, 2020, 03:16:07 PM
^^^ That's a big thumbs up!

Had to purchase additional storage space just to keep it on the thread!

Wow!

;-)

holy crow.. i didn’t realize it was that large. it was just the one from an iphone keyboard. won’t do that again.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 28, 2020, 09:25:11 PM
Thumb looks normal on my phone. Weird.

Tidied up some wiring and mocked up the radiator , one of the only pieces being used from a Dodge. Did I ever mention how much I dislike Dodges?

(https://uploads.tapatalk-cdn.com/20200129/345223b64fb0a31909db037dd2a4274c.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 28, 2020, 09:31:20 PM
Thumb looks normal on my phone. Weird.

Tidied up some wiring and mocked up the radiator , one of the only pieces being used from a Dodge. Did I ever mention how much I dislike Dodges?

(https://uploads.tapatalk-cdn.com/20200129/345223b64fb0a31909db037dd2a4274c.jpg)

Nope, please do tell......  :tongue:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 28, 2020, 09:34:56 PM
Then the engine returns, hopefully for the final time.

I'm posting pretty much as it happens. So, this may take a while.(https://uploads.tapatalk-cdn.com/20200129/361743477a8613281261cb8182d87b6d.jpg)(https://uploads.tapatalk-cdn.com/20200129/379299df21873a103439d11ed5e80f92.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on January 28, 2020, 10:06:10 PM
that thing is 100% black.. may want to check for leaks  :grin:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 28, 2020, 10:54:07 PM
Looks clean so far.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 28, 2020, 11:08:14 PM
Ken, I expect this to be running by the time I get there......

And please help me meet up with H. I've had a crush on her since the first time she wore pant suits.     :evil:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 28, 2020, 11:29:05 PM
Haul? I would like to see screaming and kicking!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on January 28, 2020, 11:45:45 PM
Haul? I would like to see screaming and kicking!

 :huh: Isn’t that what we see from Ken every time I mention him and H?  :popcorn:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 28, 2020, 11:56:11 PM
Thanks JR.

And Shawn, that's kind of a weird confession, and an even weirder place to do it.  :moreevil:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Bigdave_185 on January 29, 2020, 01:08:22 AM
Ken do you own a pant suit?  You might want to put that away somewhere he can’t find or see it.  Don’t need him pulling out a dress up kit


Sent from my iPhone using Tapatalk
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 29, 2020, 02:06:02 AM
Him and her mao suits?

Pictures are a must!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: America.Mike on January 29, 2020, 02:25:58 AM
I wanted to get away from the plastic master, so I spent some time trying to sort that out.

The '85 Chevy version is cast, but only 11/16 bore...but...direct mount and proper rod length and geometry.

The Dodge is 7/8"... not even close. ..no way that smaller bore would work with the Dodge slave. (which is 1" bore )
I'm going to try a cast slave from a 91 Chevy 3500. I'll have to redrill the mounting holes and cut the push rod.
It has a 13/16 bore, for an .85:1 ratio, compared to the Dodge's .875:1 ratio.

With this setup I can get rid of the plastic line and o-ring connections... just hope it works.(https://uploads.tapatalk-cdn.com/20200122/39bccfd7b014d93073c5c951faefa8e1.jpg)(https://uploads.tapatalk-cdn.com/20200122/efe66df591dc5642afd4497b9c653a68.jpg)
I ran a Chevy slave also. Works perfect with the heavy clutch I run.(https://uploads.tapatalk-cdn.com/20200129/6a6c30b1b91b4e3b5c84b5f224490621.jpg)


Sent from my iPhone using Tapatalk
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on January 29, 2020, 09:04:04 AM
Nice adapter Mike. Thanks for the confirmation.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on January 29, 2020, 02:35:04 PM
Get it right, people.  Hillary gets her suits from Kim Jong Un


Sent from my iPad using Tapatalk
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on January 29, 2020, 10:05:21 PM
They are still Moa suits,,,,,,,,,
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 09, 2020, 06:34:42 PM
I've hooked up the starter, flywheel, and enough wires to make it run. Was trying to spray weeds in the wind today and after killing all my neighbor's flowers, I decided to get the first new fuel tank ready to install.
(https://uploads.tapatalk-cdn.com/20200209/10764d858cb5b6c0f3b8bdfaffd70b03.jpg)(https://uploads.tapatalk-cdn.com/20200209/5bcde282da9672da8e131eb499428d6e.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 09, 2020, 06:41:27 PM
i just pulled mine! hahaha
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 09, 2020, 06:42:32 PM
Also received some beautiful GLO plastic diff covers, with horrible welds, and Bernie stickers on the inside.

 Okay, only one of those is true...

One of them is for the future D60 I have yet to rebuild. Now I have a good reason to do so.

Should give me time to send them to Don for a super paint job. On second thought, he has a history with diff covers. No offense boss...(https://uploads.tapatalk-cdn.com/20200209/7c64650b695d47c2139ec5121e5c76d3.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 09, 2020, 06:43:44 PM
i just pulled mine! hahaha
Well that's dumb,  put it back in !!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 09, 2020, 06:52:56 PM
Go kill some more flowers,,,,,,,,,,,,,,,,,,,
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 09, 2020, 06:55:12 PM
i just pulled mine! hahaha
Well that's dumb,  put it back in !!

they were empty and rusted inside. and too long for the short bed  :grin:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on February 09, 2020, 07:19:41 PM
Also received some beautiful GLO plastic diff covers, with horrible welds, and Bernie stickers on the inside.

 Okay, only one of those is true...

One of them is for the future D60 I have yet to rebuild. Now I have a good reason to do so.

Should give me time to send them to Don for a super paint job. On second thought, he has a history with diff covers. No offense boss...(https://uploads.tapatalk-cdn.com/20200209/7c64650b695d47c2139ec5121e5c76d3.jpg)
I heard that!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on February 09, 2020, 10:08:08 PM
Also received some beautiful GLO plastic diff covers, with horrible welds, and Bernie stickers on the inside.

 Okay, only one of those is true...

One of them is for the future D60 I have yet to rebuild. Now I have a good reason to do so.

Should give me time to send them to Don for a super paint job. On second thought, he has a history with diff covers. No offense boss...(https://uploads.tapatalk-cdn.com/20200209/7c64650b695d47c2139ec5121e5c76d3.jpg)
I heard that!

Funny, know what I didn’t hear? A 12v running.....  :tongue:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 10, 2020, 05:42:03 AM
Also received some beautiful GLO plastic diff covers, with horrible welds, and Bernie stickers on the inside.

 Okay, only one of those is true...

One of them is for the future D60 I have yet to rebuild. Now I have a good reason to do so.

Should give me time to send them to Don for a super paint job. On second thought, he has a history with diff covers. No offense boss...(https://uploads.tapatalk-cdn.com/20200209/7c64650b695d47c2139ec5121e5c76d3.jpg)
I heard that!

Funny, know what I didn’t hear? A 12v running.....  :tongue:

i’m ducking for cover bc there are definitely shots being fired hahah
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: cj7ox on February 11, 2020, 04:34:10 PM
 :popcorn:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 12, 2020, 09:26:14 PM
Made some progress. Going to run it on 1 tank until I have time to replace the other one.(https://uploads.tapatalk-cdn.com/20200213/8bae6134a06bee5f47300ef25344b5e6.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 12, 2020, 09:29:59 PM
ohh man.. so it runs and drives on off road diesel huh?!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 12, 2020, 09:33:07 PM
So that's my next thing at the Ridge, diesel fuel. 5 gallon cans are getting old.

I have a bunch of 30gal plastic containers, but may go with a 55.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 12, 2020, 09:33:52 PM
It's not red fuel!

http://imgur.com/a/Ugm9foi
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 13, 2020, 07:02:38 AM
vid gots no sound  :shocked:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: dave945 on February 13, 2020, 08:45:07 AM
Maybe it’s like the Prius hybrid, totally silent below 5 MPH.


Sent from my iPhone using Tapatalk
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 13, 2020, 09:18:30 AM
One more time for the guys lacking an imagination. :)

Guess I made it public. The comments should be fun.

http://imgur.com/gallery/ZUHZzCE
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 13, 2020, 02:43:04 PM
One more time for the guys lacking an imagination. :)

Guess I made it public. The comments should be fun.

http://imgur.com/gallery/ZUHZzCE

more better

‘all engines are 12 bolt’  :facepalm:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 14, 2020, 07:39:03 PM
Installed the new hydroboost and sorted out the hoses. I used parts for an '86 Chevy 3500, and the pump is for a '96 Cummins.
(https://uploads.tapatalk-cdn.com/20200215/dd63fffb07b34d5ce9be20bacf6ba0b4.jpg)(https://uploads.tapatalk-cdn.com/20200215/d9e106ab7cc544cf8a887c47025f63e5.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 14, 2020, 07:45:33 PM
The only issue I had was that all hydroboosts, (to my knowledge) and their hose counterparts, are metric, with o-ring connections. A gear box on a '73 has flare fittings.

I had to cut off the end of the pressure line to the box, transfer the old line nut, and flair the end. Pretty easy.

After that the wires were taped and loomed, and heater hoses ran.(https://uploads.tapatalk-cdn.com/20200215/6f3227297c06cbb63ed84bd125f28d55.jpg)(https://uploads.tapatalk-cdn.com/20200215/8a472e66b04fd218ecf05e645375b50b.jpg)(https://uploads.tapatalk-cdn.com/20200215/1b3d73a801c08ee572bd948bbf041193.jpg)(https://uploads.tapatalk-cdn.com/20200215/5afe72139e6d8ccaaf6646576ae4cfdd.jpg)(https://uploads.tapatalk-cdn.com/20200215/bdbd7b47010e1f959580c1dab9c5b4dd.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 14, 2020, 08:35:47 PM
Looking good. I know they make adapters for the SB, but correct hoses are cleaner and better.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 14, 2020, 10:16:47 PM
I agree. Adapters just increase the chance of leaking somewhere.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 15, 2020, 10:38:01 AM
is that an external voltage regulator?

if so, i’d scrap it and go with transpo internal 1 wire regulator for the 2nd gen alt. just requires 12 volt switched to start charging. been on the kaiser for ~4k miles and even more idle time with no issue.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 15, 2020, 03:49:03 PM
Yes. I cheated and just transferred that section of harness over from the donor since the alternator was in working order. Just trying to do it as quick as possible because I have other projects to do before summer.
...plan to straighten out bugs, etc. and build a front diff at another time.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 16, 2020, 10:33:36 PM
I tried cleaning the donor radiator, because I like old school brass, and it turned into a sprinkler.
So now I have a china version. Oh well.

Going to try to stay with using parts like the radiator, hoses, etc from a second gen...in this case a '96 Dodge 3500.(https://uploads.tapatalk-cdn.com/20200217/47d9890d3f18b2b63a9034e55a3408fa.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 16, 2020, 10:41:08 PM
Moved on to something more fun, like mounting the water to air intercooler.

After buying an entire box of 3" pipes, clamps and couplers from the Amazon, I wasted 2 hours trying to mount the cooler to the right fender. It was fighting the future air cleaner and 2 coolant tanks for the same space.

It now resides on top of the engine, but not mounted yet. No pipes needed. Only 2 silicone couplers and a soon to be built intake stub.

(https://uploads.tapatalk-cdn.com/20200217/a10348f174eb7d3b3d31509cb106db29.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 16, 2020, 10:48:04 PM
The turbo outlet was pie cut a couple times to get it low enough to clear the hood (hopefully) and get the right angle. Just need to move the harness above the cooler.

I'm not going to make this permanent until I get the transmission in, in case I need to move the engine.

First pic shows how tall it was before the modification, and if rotated clockwise the angle was way off, pointing down towards the valve cover.(https://uploads.tapatalk-cdn.com/20200217/422050fdeb0a78c74f7752f1973fa4e6.jpg)(https://uploads.tapatalk-cdn.com/20200217/4684ee008e8eb77606f87a052cf02da3.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 17, 2020, 06:37:40 AM
why water to air? limited space in the ‘73-‘80 core support? i’ve heard they’re smaller burb ever seen one first had to know for sure. where will the reservoir be? does it continuously flow?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on February 17, 2020, 12:17:29 PM
That is really good work, Kenneth, and quite the imaginative engineer!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 17, 2020, 01:50:15 PM
Interesting for sure, will it work as well as air though?

2nd gen 3500 gm platform?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 17, 2020, 08:35:53 PM
why water to air? limited space in the ‘73-‘80 core support? i’ve heard they’re smaller burb ever seen one first had to know for sure. where will the reservoir be? does it continuously flow?
You're as bad as my.....
Well I suppose I've missed some of your thread also
Check out post #140-142.
I have 2 surge tanks ordered. One for the rad, and 1 for the cooler since I can't get to the cap for filling.

For now the electric water pump will run all the time, until I hook up a temp sensor somewhere.

JR, yes they work really well. Since I'm not going to tow long grades it should be fine... just less reliable I would think. ... electric water pump, extra hoses, extra radiator, etc.
This whole engine/trans setup is a 96 Dodge 3500, according to the P-pump numbers.

Thanks Don!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 18, 2020, 08:20:44 PM
Got the brake lines back in, cooling system together, made the f *#"&"&! Dodge fan shroud fit, made an intake horn , installed a bleeder in the highest point of the cooler box, and let it run for a while. So far so good.

Next up is the air cleaner and plumbing the coolant hoses for the intercooler.(https://uploads.tapatalk-cdn.com/20200219/a62cb679ebc81f31471b7b1e0c1e3c13.jpg)(https://uploads.tapatalk-cdn.com/20200219/fb80529702990cdfe9aa24d87e4f3958.jpg)(https://uploads.tapatalk-cdn.com/20200219/5f3aeaa24f4015957b667f84e4cf8582.jpg)(https://uploads.tapatalk-cdn.com/20200219/46f7c8e8cb9c0a1fb5de22c890a7798b.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 19, 2020, 06:06:08 PM
...and prepped the trans for installation.
I forgot that the tailhousing had to be modified for the transfer case adapter, so that was the next purchase.

This is the kit from Advance Adapters.
The tailhousing has to be notched for the t/c shift shaft...(https://uploads.tapatalk-cdn.com/20200219/aa3f9e10671507829447fef1e014344c.jpg)(https://uploads.tapatalk-cdn.com/20200219/52fc3a5f1f4dd56de28d375219a1cca8.jpg)(https://uploads.tapatalk-cdn.com/20200219/c5fd2d057d14c4ab6d7b0d942ea6b36c.jpg)(https://uploads.tapatalk-cdn.com/20200219/813befdebe1995bc68b5950deab98781.jpg)(https://uploads.tapatalk-cdn.com/20200219/c935ead8e3b5cc04fb62014282bd89ea.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 19, 2020, 06:07:40 PM
....then 2 new holes drilled for the adapter. Once that was accomplished, it was sprayed with beige.(https://uploads.tapatalk-cdn.com/20200219/a2ef0070a0717e574cf692c68ae8a063.jpg)(https://uploads.tapatalk-cdn.com/20200219/2a5fe2e25baada6dda9a172accca27a3.jpg)(https://uploads.tapatalk-cdn.com/20200219/17aaaeaa1e6285dcb5d4622b29f8a2b6.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 19, 2020, 06:13:34 PM
While I had the paint flowing I went ahead and shot the new GLO rear diff cover. I mean, I felt the need to cover up Shawn's hideous welds before anyone saw them.

(Just kidding for those that don't know how we joke around here)(https://uploads.tapatalk-cdn.com/20200219/ed7cf83fbd59cbc2eb5f1536349ec821.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 19, 2020, 06:18:17 PM
Looking good
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 19, 2020, 09:19:43 PM
....then 2 new holes drilled for the adapter. Once that was accomplished, it was sprayed with beige.(https://uploads.tapatalk-cdn.com/20200219/a2ef0070a0717e574cf692c68ae8a063.jpg)(https://uploads.tapatalk-cdn.com/20200219/2a5fe2e25baada6dda9a172accca27a3.jpg)(https://uploads.tapatalk-cdn.com/20200219/17aaaeaa1e6285dcb5d4622b29f8a2b6.jpg)

we said no beige!! it’s only 50% likely to run now!! hahah

but.. i gotta admit. does look good.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 19, 2020, 10:08:12 PM
What do I do with my 12 cans?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 19, 2020, 10:49:24 PM
Come on Seth, you painted one that color...2 tone iirc.
Pepperidge Farms remembers.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on February 20, 2020, 05:53:48 AM
Good stuff Ken.


Sent from my iPad using Tapatalk
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 20, 2020, 06:05:36 AM
Come on Seth, you painted one that color...2 tone iirc.
Pepperidge Farms remembers.

i really do dig the color.

this whole build just oozes cool. clean. simple. to the point.

going to be one slick 1 ton when you get the 60 cleaned up and gone through. as it should have been from the factory. (while i liked my 1st gen cummins.. the square body chevy just looked better all the way around..)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on February 20, 2020, 08:46:42 AM
Really nice work!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 21, 2020, 09:55:57 PM
So I went with this clutch. Not the perfect choice but will work, for the price. ..13" upgrade, but still fits the smaller 1.25" input shaft.(https://uploads.tapatalk-cdn.com/20200222/a438ce52c4757fc0ccd09cc52eec062d.jpg)(https://uploads.tapatalk-cdn.com/20200222/624ac54cbd13dce02bebd08752d49c0b.jpg)(https://uploads.tapatalk-cdn.com/20200222/95cf1667dde440109a80265342b96d32.jpg)(https://uploads.tapatalk-cdn.com/20200222/1ed1665b925c664d4f740800adc7e7a2.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 21, 2020, 10:04:18 PM
Before the trans went in I took off my shoes to measure how much I needed to cut out of the transmission tunnel. Also had to modify the t/c shifter to clear my bench seat, and the new bracket that it mounts to. Dang crossover years. Pretty sure GM used a shifter from the previous ''69-72 models in the '73/74 trucks. (https://uploads.tapatalk-cdn.com/20200222/877f87c8e32770748fcb141f3a0e8875.jpg)(https://uploads.tapatalk-cdn.com/20200222/e7bfeece5a06369adc50b8a5afe77db6.jpg)(https://uploads.tapatalk-cdn.com/20200222/b8f6bc0ad9b1a53a7c504f4c849c28dd.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 21, 2020, 10:14:42 PM
That ^^^ was real fun trying to figure out without mounting the transfer case for measurements.

..and the trans is installed.
I used a 91 Chevy slave as opposed to staying with mid 80s, like the master, because the bolt pattern is wide enough to redrill to fit the nv4500 studs.
Only issue is it won't allow the bleeder to face upwards. I'll have to remove it to bleed but don't mind.

The preferred way would be to make an adapter for the earlier GM model like American Mike posted earlier, for the smaller bolt pattern, but this is the new me... time to wrap this up.

.. Dodge on the top. 91 Chevy on the rest, after drilling new holes.
Now I can order the correct length -3an hose...in this case 48".(https://uploads.tapatalk-cdn.com/20200222/e6824ca3f6e489a0e5126a7052ba1345.jpg)(https://uploads.tapatalk-cdn.com/20200222/ea8c87940d604a7f2a219471839f59ae.jpg)(https://uploads.tapatalk-cdn.com/20200222/37988fc216eef4851eb4e506bfe331b0.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 21, 2020, 10:26:39 PM
I need to sort out the transfer case and get it mounted before building a crossmember. As mentioned earlier, the old male 10 spline 205 needs to be converted to a female 29 spline.
To do this, it has to be completely disassembled and the input bearing bore machined out to 3.543", from about 3.150".

Today the Halloween themed 205 was taken apart in a careless fashion, with zero regard for the bearings, nuts, and my favorite hammer.
That took less time than it took to clear the workbench to make way for this cluster....
(https://uploads.tapatalk-cdn.com/20200222/50b4a9aad586e1e3b8c5b7c44f57cbfd.jpg)(https://uploads.tapatalk-cdn.com/20200222/ae58592fbae31f0a58627cd723fe22c3.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 21, 2020, 10:30:43 PM
I did not trust myself to machine something of this importance.....
... so I went ahead and did it anyway.

This is were it stands at the moment.(https://uploads.tapatalk-cdn.com/20200222/63987e2c16812c011928e5cfbda7862e.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on February 21, 2020, 10:42:17 PM
Boy that transfer case I bought was much cleaner than the one you kept.....  :tongue:


And it’s just a boring bar, easy peasy  :likebutton:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: America.Mike on February 21, 2020, 11:11:30 PM
This truck is turning out badass!


Sent from my iPhone using Tapatalk
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 22, 2020, 12:41:28 AM
Boy that transfer case I bought was much cleaner than the one you kept.....  :tongue:


And it’s just a boring bar, easy peasy  :likebutton:
Yeah, but you forget who's doing the boring!
Oh, and you only got 1 out of the 2 Ford t/cs. I'll be robbing parts tomorrow. Got a couple rusted gears.

Thanks Mike.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 22, 2020, 01:30:38 PM
i saw the 10 spline input and was going to ask if you were just adapting it or going to bore and put 29 spline in. it sure is turning out nice. wish i had a milling machine i have to run my stuff down to a machine shop buddy. but it’s always cool to see what he has going on down there too. sounds like it shouldn’t be too much longer before you’re motoring down the road in a newly swapped K truck. exciting times for sure!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 22, 2020, 03:36:16 PM
The reason I have a mill is because I can't trust anyone around here. Just need to spend more time using it, and learning to clean up after myself. Lol

Today I finished the bore and tore down a spare ford left hand drop 205 I got from the same owner of the 12v engines. It looks like it only had a few thousand miles on it when someone rebuilt it. I'll be using the gears and possibly bearings from it (USA timkens) instead of the new ones in the rebuild kit I purchased.

My gears are pretty rust/pitted.(https://uploads.tapatalk-cdn.com/20200222/30dc1440ff09e7c04b8cbc35db686ad4.jpg)(https://uploads.tapatalk-cdn.com/20200222/1f8a19731631e579be3b17f033182263.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 22, 2020, 03:44:06 PM
The ford 205...

I absolutely hated the front pinion on my tc. It was very difficult to remove the front driveline/CV joint because of bolt location.
The ford tc has a longer pinion ... better bolt access... so that should be an improvement.

(https://uploads.tapatalk-cdn.com/20200222/f30bce819580c75a43703173b43d58c2.jpg)(https://uploads.tapatalk-cdn.com/20200222/dad507a3588618c845944000dfb3adb9.jpg)(https://uploads.tapatalk-cdn.com/20200222/197f25cede5521c2f0736e8f650d3eb1.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 22, 2020, 09:08:38 PM
that’s awesome. and aggravating. how much of the ford case are you using? just front and rear output? getting a new 29 spline input i take it.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 22, 2020, 09:14:05 PM
i think the chevy and dodge case that i’ve gotten in to lately both had threads in the yoke and not pass through holes like yours. so that must be a year thing.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 22, 2020, 09:30:49 PM
Think Shawn has some nice caps for those. Plus I think you can just drill em out for U bolts.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 22, 2020, 10:01:08 PM
that’s awesome. and aggravating. how much of the ford case are you using? just front and rear output? getting a new 29 spline input i take it.
Everything except the case, speedometer drive (plastic...mine's metal) and input.. that came in the adapter kit.... that I had to bore the case for.
JR, I'm running a CV in the front driveline. It has threaded caps. If I have to replace it I'll go to a ubolt setup, or maybe a flange style.

The 29 spline input is still wrapped up in this pic.(https://uploads.tapatalk-cdn.com/20200223/9a8b0a9949759b7beddf38452cbd6a43.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 22, 2020, 10:29:47 PM
that’s awesome. and aggravating. how much of the ford case are you using? just front and rear output? getting a new 29 spline input i take it.
Everything except the case, speedometer drive (plastic...mine's metal) and input.. that came in the adapter kit.... that I had to bore the case for.
JR, I'm running a CV in the front driveline. It has threaded caps. If I have to replace it I'll go to a ubolt setup, or maybe a flange style.

The 29 spline input is still wrapped up in this pic.(https://uploads.tapatalk-cdn.com/20200223/9a8b0a9949759b7beddf38452cbd6a43.jpg)

very nice.

are the drive gears the same? (same groove count) that’s definitely something to consider as well as for tuning the speedo.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 24, 2020, 09:07:07 PM
So, the front output shaft on the Ford tc is much stouter, so I'll use that whole assembly. The rear output shaft is very similar, except for having a plastic speedometer gear. I went to swap it for my steel gear and the ford shaft is larger diameter, just where the speedo mounts. The rear housing is also different, so I had to clean my old one .

The '73 205 was cleaned, painted, and I sprayed some red oxide on the inside.(https://uploads.tapatalk-cdn.com/20200225/e67e1de76b96f55d5be4f2c8369baf1b.jpg)(https://uploads.tapatalk-cdn.com/20200225/716251be282bf1b8cd2b7a383fbee228.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 25, 2020, 11:43:48 AM
Difference in the rear housings. First pic is driver's drop ford (left) compared to the right side drop. Speedometer driven gear rides high. My chebby rides low. Because of this the internal drive gears have opposite teeth direction.

More useless info to absorb Don's monthly pixie allotment.(https://uploads.tapatalk-cdn.com/20200225/f47bdc9641a103906f5049d5d5ae70b7.jpg)(https://uploads.tapatalk-cdn.com/20200225/8e878b4f526acdce1caed7e6728351a2.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 25, 2020, 12:57:33 PM
can’t you just flip the gear over..?








 :grin:

good to know for future reference
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 25, 2020, 02:37:56 PM
can’t you just flip the gear over..?








 :grin:

good to know for future reference

Still spins the same way,,,,,,,,
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on February 25, 2020, 05:52:08 PM
In Ken’s case that would always be left
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 25, 2020, 07:23:05 PM
can’t you just flip the gear over..?





‘twas a joke. i laughed to myself picturing everyone turning it over in their head and saying ‘it still spins the same way!’




 :grin:

good to know for future reference

Still spins the same way,,,,,,,,
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 25, 2020, 07:23:26 PM
Had to bring H into it?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on February 25, 2020, 07:47:34 PM
Had to bring H into it?

Absolutely, it’s been awhile plus I owed him for some detuned 24v comment
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 26, 2020, 10:14:25 PM
Finished the tcase.(https://uploads.tapatalk-cdn.com/20200227/44d62ad03ceca2bc5b2a18422536123c.jpg)(https://uploads.tapatalk-cdn.com/20200227/b96b0594754aca90c6e19df8eb2f5935.jpg)(https://uploads.tapatalk-cdn.com/20200227/74f8c1915aed3df91a62d652ec7aeecb.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 26, 2020, 10:24:30 PM
I hate to bad-mouth a company, but I will. The instructions that came with the adapter kit were terrible. I downloaded the full version from their site and that was also terrible.
I had to download the version for a GM 4500 trans just to get a pic of how the tailhousing was supposed to look after cutting out the notch for the tc shift rail.
The box of parts included a piece of square tubing that has 4 holes that matches the pattern of the transmission mount, but no pics, nor explanation. It's about 1.5"... why would anyone want to raise the trans another 1.5"? My tc is already hanging way too low. More on that later.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 26, 2020, 10:27:28 PM
Oh, and got the -3an hose ran to the slave. Man what a difference... pedal feels like butter, especially compared to the old mechanical setup!(https://uploads.tapatalk-cdn.com/20200227/2de969491c36a9d6ab9d736d33582baa.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on February 26, 2020, 10:27:48 PM
As someone who manufactures clocking rings and np205 ones at that it’s for mall crawlers.......


It looks good though!  :likebutton:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 26, 2020, 10:32:11 PM
Then installed a GM air cleaner.
Some 4" stainless exhaust scuffed up on the belt sander, a couple couplers, and a LS style air box . Drilled a couple holes in the inner fender for it to snap into, and almost done.(https://uploads.tapatalk-cdn.com/20200227/bf8629feb472333815f82bcf87250a5f.jpg)(https://uploads.tapatalk-cdn.com/20200227/eecf3e3fa2691cebaa6c9fb1a31160bd.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 26, 2020, 10:33:35 PM
As someone who manufactures clocking rings and np205 ones at that it’s for mall crawlers.......


It looks good though!  :likebutton:
What you saying?

If it's bad why wait for me to install it knucklehead!!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on February 26, 2020, 11:34:02 PM
As someone who manufactures clocking rings and np205 ones at that it’s for mall crawlers.......


It looks good though!  :likebutton:
What you saying?

If it's bad why wait for me to install it knucklehead!!

Sorry, no comprende this must be some backwards liberal logic.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 27, 2020, 01:16:54 AM
The air cleaner look great. I need one for the SUB and have the 5.3 in the shed stored, will have to look at it.

Does it flow enough air?
Title: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on February 27, 2020, 09:03:48 AM
Just a rudimentary volume calculation would say yes. 5.3l x 5000 rpm = 26,500l.

5.9l x 3000 rpm = 17,700


Sent from my iPhone using Tapatalk
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 27, 2020, 11:00:34 AM
Just a rudimentary volume calculation would say yes. 5.3l x 5000 rpm = 26,500l.

5.9l x 3000 rpm = 17,700


Sent from my iPhone using Tapatalk

Thanks brainiac...
I went with the less precise redneck method. I ordered a Wix for a 6.0, the thick "H/D" one for a 5.3, with a wire mesh backing to keep it out of the turbo :), compared the size to my LML, and moved forward. I still need to trim off the inlets because they don't match up to the fender openings....and not going to cut the fender.
...and Shawn still didn't answer my question I see.
Is it because the plate is aluminum that makes it less than desirable? I have to use something to adapt the figure 8 style and retain the input bearing. Only stronger option I could see is to use the actual Dodge 205 so no adapter would be needed...?...
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on February 27, 2020, 12:08:42 PM
You’re welcome redneck


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 27, 2020, 02:39:00 PM
You’re welcome redneck


Sent from my iPhone using Tapatalk
I didn't mention the flaw in your math.
It has to do with forced induction.

Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Farmer Jon on February 27, 2020, 03:01:19 PM
Nice touch with the air cleaner.

Sent from my Pixel 2 XL using Tapatalk

Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 27, 2020, 04:43:35 PM
My 6.2 is turbo'd, but only about 6 psi.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on February 27, 2020, 07:42:06 PM
Ken, I didn’t understand that was an actual question. Assumed you were blowing me more liberal logic.

Anyhow, no I don’t think the alum is an issue. Run it just brace the trans and t-case well and assume the connection is not a structural connection which they are not even oem setups.  :likebutton:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 27, 2020, 08:44:50 PM
Ken, I didn’t understand that was an actual question. Assumed you were blowing me more liberal logic.

Anyhow, no I don’t think the alum is an issue. Run it just brace the trans and t-case well and assume the connection is not a structural connection which they are not even oem setups.  :likebutton:
Rog.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 27, 2020, 08:59:27 PM
So I just spent an entire day moving the engine, to be able to raise the trans/transfer case.
Originally, I had set up the motor with the fan blade perpendicular to the radiator, without cutting the firewall. This gave the fan about 1/4" clearance. I absolutely will not run an electric fan on a truck. Call me old fashioned.

A before pic of the tc. From videos on the internet, mostly of 1 tons, it looks about right....but being a 3/4 ton, with a 6" tall frame (instead of 8" on the 1 tons), the tc looks weird....too low.... about 2" lower than original.(https://uploads.tapatalk-cdn.com/20200228/7a1a7aae4dd2591e1172e91f041911fb.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 27, 2020, 09:08:13 PM
...If I raise it the fan hits the radiator.
After measuring from multiple points, I decided to pull the engine mounts to do some more slotting. The engine was moved back an additional 3/4", raised the tc almost 2", which opened up the firewall clearance again.

Not trying to write a book, but maybe these details will save someone a headache in the future.

Here's the after shot:

(https://uploads.tapatalk-cdn.com/20200228/6f306f21c3e484bae7f19671e3720d76.jpg)(https://uploads.tapatalk-cdn.com/20200228/2a157399cb2ef534a41a215dff640514.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 27, 2020, 09:12:43 PM
The Dodge transmission mount, and the plate it bolts to, were reused.
I had to redrill the plate to move it forward to clear the new tc adapter.

Second pic is the 2" square tube mount spacer. ... don't have a clue how that would help make anything fit.(https://uploads.tapatalk-cdn.com/20200228/43560e2c575720f886485b5552fdc8b7.jpg)(https://uploads.tapatalk-cdn.com/20200228/7e83406917c28df85bf66237d8784f6e.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 27, 2020, 09:19:36 PM
What's awesome is that I was able to reuse the gm crossmember...it was the perfect height once the trans was raised to the current location.
... just cut out the large holes in the mount area and welded in a piece of 2" channel.
...then drilled new bolt holes in the frame, upsized to 1/2" with plates under the heads of the bolts.

Once this thing is driveable, I'll put it on the hoist and add some reenforcement.(https://uploads.tapatalk-cdn.com/20200228/633c0844bb7cb73383f33cb860da8539.jpg)(https://uploads.tapatalk-cdn.com/20200228/9b6aef4a451a26ed025f3b555962e321.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 27, 2020, 10:05:26 PM
Wish I had pics but that is just how my 77 looked. I did have a skid plate with 2 of those cross members though

Just make sure it has a nice skid plate (it was 1/4 thick) not like the bozo stamped unit we have on the dmax.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 28, 2020, 07:58:17 PM
Shortened the rear driveline 3.5", mainly because I'm too tight to buy one.
Got it in and ran through the gears to make sure the transmission worked. So far so good.(https://uploads.tapatalk-cdn.com/20200229/9b8f57ad3c54868ee01374af22018f40.jpg)(https://uploads.tapatalk-cdn.com/20200229/0d8afd454003812f8315b95753611d02.jpg)(https://uploads.tapatalk-cdn.com/20200229/1d8c5d68f22f0d63cb557d02fd1f358b.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on February 28, 2020, 08:31:16 PM
 :likebutton:

Did t know you were qualified for such things.....
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on February 28, 2020, 08:32:57 PM
:likebutton:

Did t know you were qualified for such things.....

no one said he was qualified. he just did it..  :laugh:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Bob Smith on February 28, 2020, 08:54:18 PM
give the guy a bit of a break, he needs one
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 28, 2020, 10:46:22 PM
:likebutton:

Did t know you were qualified for such things.....
I redlined the motor in 5th gear on jack stands and it didn't blow up and my teeth didn't fall out, is that good enough? Lol
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 28, 2020, 11:56:19 PM
Brave men IF YOU DID,,,,,,,,,,,,
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 29, 2020, 01:19:01 AM
Oh I did JR. Was more worried about the dry rotted swampers disintegrating tho.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on February 29, 2020, 01:27:06 AM
Oh I did JR. Was more worried about the dry rotted swampers disintegrating tho.

But no pics or video, right??
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 29, 2020, 09:29:23 PM
JR, you need to put some gummy bears on that hook if you want me to bite again...key word... again.

Rebuilt the steering gear while I was there so I could reinstall the column.

Bled and adjusted the brakes. Threw the front tires on, and installed a new slave reservoir. Also built a temporary downpipe that points at the ground.

...and finally test drove it. First time in a few years. I missed the ol girl.
Next up, plumbing the intercooler once I receive a different surge tank, hopefully one that fits. (3rd one I've ordered).(https://uploads.tapatalk-cdn.com/20200301/cfd718f9e06d4bd30b0189d9566fa925.jpg)(https://uploads.tapatalk-cdn.com/20200301/b849585da47b0134a28345f9c315bc72.jpg)(https://uploads.tapatalk-cdn.com/20200301/6d06be80d3efe51887878898168241f8.jpg)(https://uploads.tapatalk-cdn.com/20200301/93ee883f3e21932b2eac9408567095f3.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on February 29, 2020, 09:35:25 PM
Yes, I'm replacing the Pontiac blue wiper motor..
She has a horrible amount of vibration, even for a Cummins. Feels like the engine is sitting on the dash. It didn't do that when I was running it without the transmission so I'll have to figure it out.
..but man the brakes and clutch are pretty awesome. It's never felt that good. P/s is better also, even with the added weight.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 01, 2020, 07:52:57 AM
Yes, I'm replacing the Pontiac blue wiper motor..
She has a horrible amount of vibration, even for a Cummins. Feels like the engine is sitting on the dash. It didn't do that when I was running it without the transmission so I'll have to figure it out.
..but man the brakes and clutch are pretty awesome. It's never felt that good. P/s is better also, even with the added weight.

for the vibration.. i don’t remember exactly how you mounted the trans to the cross member. was there a factory bushing or did you just bolt it right to the trans crossmember. 

i know on my dads we bolted a piece of 2” channel to the trans that extended out wider than the trans bolt holes and used essentially 2 thick round body bushings about 8” apart (for twist stability and vibration dampening..)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 02, 2020, 09:08:28 PM
Well, remember how I mentioned that it felt like the engine was sitting on the dash? Yeah...
When I moved the engine back, and raised the tc up, I should've looked for interference on top of the bellhousing.
:rollseyes
... that was fun to fix, but it's quite smooth now.

Here's my high tech temporary downpipe. I have a 4" on order.(https://uploads.tapatalk-cdn.com/20200303/c7415f4f710c3b6f3f9c847c7c23821e.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 02, 2020, 09:16:17 PM
I also drove this thing home yesterday, about 10 miles. It was very lackluster.. sounded great but acted like the turbo wasn't lighting off. I was quite disappointed, so today I hooked up a boost gauge and threw some cleaner in the fuel. My employee went along on a test drive since he has more experience with turbos, and on the 2nd hard acceleration something happened and it smoked the tires in 3rd, about 35mph. Don't know what caused it, and really don't care. Now I'm happy with it.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on March 03, 2020, 06:10:44 AM
Good to hear!


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 03, 2020, 07:56:03 AM
I also drove this thing home yesterday, about 10 miles. It was very lackluster.. sounded great but acted like the turbo wasn't lighting off. I was quite disappointed, so today I hooked up a boost gauge and threw some cleaner in the fuel. My employee went along on a test drive since he has more experience with turbos, and on the 2nd hard acceleration something happened and it smoked the tires in 3rd, about 35mph. Don't know what caused it, and really don't care. Now I'm happy with it.

it probably pulled the 5.3 filter through the box and ate it  :grin:

either way.. good to hear.

does the truck have a waste gate? maybe it was stuck slightly open and needed a good beating on to loosen up.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on March 03, 2020, 07:57:50 AM
I theorize that maybe the H bumper sticker fell off, I mean that would be a lot of weight for even a cummins to overcome. :evil:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 03, 2020, 08:24:45 AM
I also drove this thing home yesterday, about 10 miles. It was very lackluster.. sounded great but acted like the turbo wasn't lighting off. I was quite disappointed, so today I hooked up a boost gauge and threw some cleaner in the fuel. My employee went along on a test drive since he has more experience with turbos, and on the 2nd hard acceleration something happened and it smoked the tires in 3rd, about 35mph. Don't know what caused it, and really don't care. Now I'm happy with it.

it probably pulled the 5.3 filter through the box and ate it  :grin:

either way.. good to hear.

does the truck have a waste gate? maybe it was stuck slightly open and needed a good beating on to loosen up.
That's what I was originally thinking but it wasn't smoking. I think something was going on with fuel. Injection pump maybe.
Funny you mentioned air filter. That was pulled out and a Dmax version installed. It has less pleats, but made zero difference. (https://uploads.tapatalk-cdn.com/20200303/7d2afe18dc1ae710ec20cd9eff800260.jpg)(https://uploads.tapatalk-cdn.com/20200303/d2f5f4197c5ca4037c4a9ef0f5145303.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 03, 2020, 08:40:05 AM
could have been IP or maybe just funky injectors. fuel heated up/engine warmed up. got compression back and/or cleaned out some injectors.

glad she’s all good now though.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 03, 2020, 09:03:56 PM
Replaced the rear diff cover today. Had ordered some correct length, 5/16, black studs. My favorite vehicle of 30+ years and didn't realize I needed 3/8".

So we went unconventional... exhaust studs and nuts sourced from my parts house.
The rear mudflap hides it anyway.(https://uploads.tapatalk-cdn.com/20200304/284c8fafb44a1a4d50733aad67910138.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 03, 2020, 09:06:56 PM
^^^ Steampunk-ish :)

Started on the water to air plumbing again. This is the 3rd surge tank I've tried, and still have to modify it.
More on that tomorrow.(https://uploads.tapatalk-cdn.com/20200304/fd1d04e92e8c2cec912f862b7a6bf164.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on March 03, 2020, 09:49:15 PM
How much water does the system use?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 03, 2020, 10:13:16 PM
How much water does the system use?
I have no idea. Maybe a gallon with the amount of hose I'm using?.. maybe a little more
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on March 03, 2020, 10:14:44 PM
That's enough to cool the charge?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 03, 2020, 10:25:47 PM
Plenty of guys run them. Water is more efficient than air. I guess I'll let you know after I melt some pistons.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on March 03, 2020, 10:48:49 PM
Replaced the rear diff cover today. Had ordered some correct length, 5/16, black studs. My favorite vehicle of 30+ years and didn't realize I needed 3/8".

So we went unconventional... exhaust studs and nuts sourced from my parts house.
The rear mudflap hides it anyway.(https://uploads.tapatalk-cdn.com/20200304/284c8fafb44a1a4d50733aad67910138.jpg)

Looking good  :likebutton:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 04, 2020, 06:50:42 AM
i didn’t realize that the truck had air bags on it. happen to remember what brand/kit they are? i found a set from firestone that look really appealing.. just wasn’t sure how they’d be. any more pics of your setup?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 04, 2020, 08:36:32 AM
Firestone. Don't know what number it was.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 04, 2020, 08:38:27 AM
Firestone. Don't know what number it was.

perfect. that’s the kit i was looking at too.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on March 04, 2020, 08:40:53 AM
Different kit but I had the Firestone ride-rite kit on my dually and it worked well.


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 04, 2020, 08:52:14 PM
Spent some time trying to find a good place to put a surge tank for the intercooler, high enough to prevent air from getting trapped. That's the only drawback from mounting the cooler on top of the engine.
The reason for the tank in the first place is because the cooler's small radiator has a cap that's inaccessible, and also lower than the cooler.

Since I have a taller, cowl induction style hood, I decided to mount the tank above the fuel filter.
.. this required some mods to the tank.

I cut off the bottom bung first, and welded it shut. Then took a 3/4" aluminum ac line and made a nipple that points towards the firewall.(https://uploads.tapatalk-cdn.com/20200305/cc0c6f5f2e461c4e96a978f07d50aad2.jpg)(https://uploads.tapatalk-cdn.com/20200305/c916e413531bcb59640133c0896f8b2b.jpg)(https://uploads.tapatalk-cdn.com/20200305/b4e4acabaf6b89229cafe78c13b74cd1.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 04, 2020, 08:55:30 PM
Made a bracket for the tank and mounted it, then ran a "steam vent" hose to the top of the cooler to keep air from being trapped.
(https://uploads.tapatalk-cdn.com/20200305/cf7fb1109d45f51d6a2672b6c075b781.jpg)(https://uploads.tapatalk-cdn.com/20200305/9eeeb9e7d541daacf6a0c6404b92b365.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 04, 2020, 08:57:03 PM
Built another bracket for the Bosch water pump and mounted it behind the grill.(https://uploads.tapatalk-cdn.com/20200305/b9975a40efd083b92d7515cce52ae02f.jpg)(https://uploads.tapatalk-cdn.com/20200305/39bf04f5126a7bc0ba32a443b4f7e3de.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 04, 2020, 09:00:56 PM
..and finally found a good use for these Euro style clamps I had in the shed. Regular worm clamps tend to destroy silicone hoses.

Once the air was purged, she held right at 6.5 qts JR.(https://uploads.tapatalk-cdn.com/20200305/f5aec3efbea4dcbf7c8bb6c306c041a3.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on March 04, 2020, 09:48:40 PM
So it just circulates or does something cool it?

Did a little reading on it yesterday, seems very efficient.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 04, 2020, 10:30:09 PM
The cooling fan cools it. It has its own radiator in front of the condenser.
Basically the same as what Nick put in Don's suburban for the SC.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on March 05, 2020, 08:34:15 AM
As always, great fab skills Ken!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Bigdave_185 on March 05, 2020, 09:28:27 AM
Ken said “nipple” lol


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 05, 2020, 09:46:51 AM
Dang swampers won't last 20 years(https://uploads.tapatalk-cdn.com/20200305/cc324e2c7f8bb3b1b7b9497c2c19e8bb.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: EL TATE on March 05, 2020, 10:13:24 AM
lol, funny how that works huh?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on March 05, 2020, 10:51:48 AM
The cooling fan cools it. It has its own radiator in front of the condenser.
Basically the same as what Nick put in Don's suburban for the SC.

Guess I missed that, just a smaller more eff system.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 05, 2020, 11:14:17 AM
lol, funny how that works huh?
Haha. I knew it was going to happen yet I still had to drive it home yesterday. At least it was a back one.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on March 05, 2020, 12:52:46 PM
Dang swampers won't last 20 years(https://uploads.tapatalk-cdn.com/20200305/cc324e2c7f8bb3b1b7b9497c2c19e8bb.jpg)
The junk they sell these days, well, those days

;-)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 05, 2020, 08:09:16 PM
Priced some radial swamper replacements today. That's not going to happen.... about 100 more a piece than what I paid in the 20th century.
Have some cheapo Hercules MTs on order. Probably going to burn them off anyway.

..but did fix the 4wd shifter today. The adapter kit did not mention anything about this issue.

Just made a new linkage. ..new one on the right. Works ok, but still need a front driveline.(https://uploads.tapatalk-cdn.com/20200306/1c6d2367e66205dffaa0c2e43518c297.jpg)(https://uploads.tapatalk-cdn.com/20200306/388f44df73ef1e332203711bd6ed5bf4.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Sammconn on March 05, 2020, 09:08:57 PM
Come on Ken. Flip it around and it will fit.

 :knucklehead:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on March 05, 2020, 09:58:41 PM
Priced some radial swamper replacements today. That's not going to happen.... about 100 more a piece than what I paid in the 20th century.
Have some cheapo Hercules MTs on order. Probably going to burn them off anyway.

..but did fix the 4wd shifter today. The adapter kit did not mention anything about this issue.

Just made a new linkage. ..new one on the right. Works ok, but still need a front driveline.(https://uploads.tapatalk-cdn.com/20200306/1c6d2367e66205dffaa0c2e43518c297.jpg)(https://uploads.tapatalk-cdn.com/20200306/388f44df73ef1e332203711bd6ed5bf4.jpg)

Ford superduty f250/f350 99-04 (possibly newer) had 1350 cv front shafts FYI
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 05, 2020, 10:09:38 PM
get a set of terra grappler G2s and call it a day.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on March 05, 2020, 10:13:32 PM
Why name brand? Don is happy with his tires, my maxxis are doing great too.

Not a long highway truck and you wan traction, right.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 05, 2020, 10:21:49 PM
I hear you guys but it's hard to beat swampers in desert, rocky terrain. Granted, the ol girl probably will be stuck in mulch beds along with big D from now on....

Shawn, will it work on the 44? Or just the 60? Don't they have a flange tc mount?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on March 05, 2020, 11:23:38 PM
You can get the flange mount at the t-case, I know Jess at high angle has them or can make them. As for the 44 it’s most likely 1310 so conversion ujoint or swap the yoke. Tate can help in this regard. Maybe get that 60 tossed under their with correct yoke. However it’s an inexpensive way to get a cv front shaft.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on March 06, 2020, 09:39:12 PM
Why name brand? Don is happy with his tires, my maxxis are doing great too.

Not a long highway truck and you wan traction, right.
X2 on that. These cheapo Federals are frikin great. I was commenting tonight to my wife on the way home from date night how nice they ride...now 6,000 miles into the tread compound
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on March 06, 2020, 09:42:03 PM
I hear you guys but it's hard to beat swampers in desert, rocky terrain. Granted, the ol girl probably will be stuck in mulch beds along with big D from now on....

Shawn, will it work on the 44? Or just the 60? Don't they have a flange tc mount?
Amen to that!

I think I've said before that Swampers were the Special Forces guys fav tires for their modded Hummers. Look cool too on a jacked up HMMV
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 06, 2020, 10:04:59 PM
Wrapped and installed the 4" downpipe.. plenty of firewall and a/c case clearance....(https://uploads.tapatalk-cdn.com/20200307/4926a257bb97ab883bb0b72a599deb00.jpg)(https://uploads.tapatalk-cdn.com/20200307/4f7e08aa5f99062a1adcac5385e8e896.jpg)(https://uploads.tapatalk-cdn.com/20200307/dc3fdd1b73b243d58b860ee421b0e722.jpg)
(https://uploads.tapatalk-cdn.com/20200307/746112fed50dd2d2b7d3378c54bd6803.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 06, 2020, 10:11:34 PM
...and scrounged around for some exhaust pipe. Best I could come up with, without spending money, was a 5" stack off of a big truck.
It was sliced and diced, partially wrapped near the transfer case, and installed.(https://uploads.tapatalk-cdn.com/20200307/e47141bb2c53dae69654df6e0d5e4727.jpg)(https://uploads.tapatalk-cdn.com/20200307/8a58bae29c5250f731807d1d994c20c4.jpg)(https://uploads.tapatalk-cdn.com/20200307/0acca85861e68e9b5d0ec3b0ee2a33c5.jpg)(https://uploads.tapatalk-cdn.com/20200307/56ebb861909704f462027c507af18298.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 06, 2020, 10:19:45 PM
Bought a truck this morning, sold it by noon, and had new tires by the time I went home. Personal best vehicle flip.

...FYI $920 out the door.(https://uploads.tapatalk-cdn.com/20200307/49a7d4cbb05736b66e268ceb6fe5ef3e.jpg)(https://uploads.tapatalk-cdn.com/20200307/228bf171d66d973d78f27f26abb4b36a.jpg)(https://uploads.tapatalk-cdn.com/20200307/33550942d73e22320a096d723cd4179b.jpg)(https://uploads.tapatalk-cdn.com/20200307/6cc3d1d934510c56742787ceb56c1efa.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on March 07, 2020, 08:04:19 AM
Nice looking truck, really like that rear bumper.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 08, 2020, 06:42:06 PM
for sure. i dig that rear bumper. any more pics of it?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 08, 2020, 09:38:55 PM
for sure. i dig that rear bumper. any more pics of it?
Post numeral uno.

It didn't originally have the snowbird mudflap. I'm one of the only people I know that actually got a ticket for no flaps. ...along with exhibition of speed, open headers, no tags, and improper use of a turning lane.  (was smoking tires in the middle of the main drag). Still let me drive it home tho.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Bob Smith on March 08, 2020, 10:18:48 PM
But man was it ever fun. Kids anyway :popcorn:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 08, 2020, 10:36:25 PM
But man was it ever fun. Kids anyway :popcorn:
Still is Bob!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 09, 2020, 07:40:32 AM
yea.. that’s very cool.

was this something you did in HS shop class or was it post purchase at some point?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 09, 2020, 09:36:55 PM
It was owned by a welder. He built the rear bumper that tied into steel fender flares, that tied into h/d running boards... about 80% done when he died, then was finished in shop class. It was definitely one of a kind, but they started cracking from 4 wheeling so I redid everything, leaving the flares for a few years....then replaced the body and cleaned up the only part left... the rear bumper, and then made the front one.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 10, 2020, 08:00:55 AM
i really like how clean it is. towards the front of the bumper.. is there anything tying it to the frame? or all cantilevered from the rear mounts? i like how’s it’s a tad wider than the lower bed panel to act as a step too. but not wider than its widest point to keep it clean.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 10, 2020, 09:02:08 AM
It's not tied to the frame. Originally it was bolted to the bed, but now just floating.

Edit: I lied. It is bolted to the bed sides, with rubber spacers.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 10, 2020, 09:25:08 PM
Plumbed the A/C:(https://uploads.tapatalk-cdn.com/20200311/f9ca36433eb508b7b1b161fedbc1b847.jpg)(https://uploads.tapatalk-cdn.com/20200311/cf09042bbbda841066e5b6e554b2e85c.jpg)
(https://uploads.tapatalk-cdn.com/20200311/d8743d82b5d283ae37191ca2e4ee20e0.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 10, 2020, 09:31:27 PM
Then my biggest fear came to fruition. When I rerouted the serpentine belt, I was hoping I had enough wrap on the alternator. I don't. With the a/c compressor on, she squeals intermittently on acceleration. It will only get worse as ambient temps rise.

..so I did what any good mechanic would do, I turned the a/c off and started fitting the hood so I could literally cover up the problem.

Just trimmed a little to clear the intercooler surge tank.
Also reinstalled the grill, then drove home with the windows down.(https://uploads.tapatalk-cdn.com/20200311/be783a3df4db04edb8e5a6da10a2877d.jpg)(https://uploads.tapatalk-cdn.com/20200311/6c1aff907290ce1819b41cd8182a1e32.jpg)(https://uploads.tapatalk-cdn.com/20200311/5e0d70901a760a7ec37bfc4776d3effb.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: wyorunner on March 11, 2020, 07:03:34 PM
Wow, nice job Ken! I like this, I spend some time away from the forum and come back to a completed Cummins Chevy! Great work!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 11, 2020, 09:17:06 PM
Thanks!

You guys get settled in? Been wondering if maybe they don't have internet over there
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Sammconn on March 12, 2020, 12:18:12 AM
What...it’s swapped .... and running .... under its own power.... 13 pages.

Something must be wrong here.














Well done Ken! Looks good. 
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: wyorunner on March 12, 2020, 02:12:34 AM
Thanks!

You guys get settled in? Been wondering if maybe they don't have internet over there
We were settled by mid January! Had a house and a tacoMa in December, all our belongings showed up on Jan 2. And yes they do indeed have internet! I just opted to take some time off interneting while she was without a seat to sit in at work and was home most of the time! Was a wonderful couple months!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on March 12, 2020, 07:18:52 AM
Good to hear Turner.


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 12, 2020, 11:34:31 PM
What...it’s swapped .... and running .... under its own power.... 13 pages.

Something must be wrong here.














Well done Ken! Looks good.
I tried to do it so fast that no one would have time to DOT it up!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on March 13, 2020, 09:56:07 AM
Ha!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 13, 2020, 07:24:06 PM
It's official.(https://uploads.tapatalk-cdn.com/20200313/9eeffd9fee2da657dffae06eaba2fd33.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on March 13, 2020, 08:52:23 PM
Nice!  Looks like you cleaned it up too


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on March 13, 2020, 09:21:15 PM
 :likebutton: Even with the waterdrops!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 13, 2020, 10:11:23 PM
Nice!  Looks like you cleaned it up too


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Naw, we got one heck of a storm this afternoon. Worse than anything we got in the monsoons last year. Weird
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 26, 2020, 10:08:05 PM
This week I mustered up the courage to tackle the belt issue. Not much clearance to work with, but started by adding an idler pulley between the AC and alternator, which required a longer belt.(https://uploads.tapatalk-cdn.com/20200327/4a3b83200b48f70cc698ecad234410de.jpg)(https://uploads.tapatalk-cdn.com/20200327/3e77aa12060f54462b664e101e27629f.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 26, 2020, 10:13:43 PM
This is the original setup, that I don't recommend doing.
I should've bought a kit. You won't hear me say that very often, but would've been as cheap and a heck of a lot less frustration.(https://uploads.tapatalk-cdn.com/20200327/b0cd749093108ba9dec0b6a870511c83.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 26, 2020, 10:28:30 PM
The problem with my design, besides the fact that it was my design, was tensioner location. It's in the middle of the accessories instead of the tail end, like most serpentine setups. The crank pulley is pulling the tensioner over because of the load on the backside...the AC and alternator.

Long story shorter; I ended up welding the upper tensioner solid, buying a Cummins tensioner, and building a bracket to locate it under the alternator, upside down in the factory location. It uses a countersunk bolt in the original tensioner mount hole, and 2 of the lower compressor mount holes. (Not fun to get perpendicular)

So a list of parts I ended up with: 5 idler pulleys of various sizes and materials (plastic and steel), 2 tensioners, 6 belts, and 11 busted knuckles.

Hard to get a finished pic, but it finally works!(https://uploads.tapatalk-cdn.com/20200327/c0721c0db7f9af2f2ae7dcc9ac401880.jpg)(https://uploads.tapatalk-cdn.com/20200327/66c610e02cc63137a8b5ccfb83d4c31d.jpg)(https://uploads.tapatalk-cdn.com/20200327/22ab5c9a75b356d53bf1834c3fdf41e0.jpg)(https://uploads.tapatalk-cdn.com/20200327/377221040281e8da196de703c5278140.jpg)(https://uploads.tapatalk-cdn.com/20200327/0a0df069fda36493d8409dd5592b41d6.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on March 26, 2020, 10:45:03 PM
11 huh? Somehow got your wanker somewhere it shouldn’t have been again?   :huh:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 26, 2020, 10:51:31 PM
11 huh? Somehow got your wanker somewhere it shouldn’t have been again?   :huh:

hahah

but yes. i bet a kit would have been quicker/most cost effective
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 27, 2020, 01:10:05 AM
11 huh? Somehow got your wanker somewhere it shouldn’t have been again?   :huh:
At least someone got it
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on March 27, 2020, 06:25:33 AM
That looks like a Rube Goldberg machine....


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 28, 2020, 09:43:40 PM
That looks like a Rube Goldberg machine....


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Isn't she dead by now?

Might as well continue this thread.
Ordered, and received, some Dakota rtx series gauges. I went this route because they are expandable, utilizing the 2 displays in the speedo and tach gauges for a multitude of inputs. In my case boost and egts.

The cluster has one larger module that excepts most of the inputs.
I started by cutting off the original cluster connector and marking the wires, then soldering in longer wires to reach the new module.(https://uploads.tapatalk-cdn.com/20200329/98bbd2ac0eb9d27abce0d0873688c38f.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 28, 2020, 09:54:55 PM
In addition to the main module, I had to separately purchase modules and sensors for the boost and egt, and a module/converter for the (diesel) tach.

I hooked up a "W" wire in the alternator for an rpm reference.

Random pics of the process and 4 modules. I ended up using Velcro to stack them up behind the radio.... good part is that they are all Bluetooth , although later I found out that the tach converter requires you to push a button on it to enter programming. No biggy. Once it's set it's done.



(https://uploads.tapatalk-cdn.com/20200329/353e06b273cdb0c60f71c17b4804bb0d.jpg)(https://uploads.tapatalk-cdn.com/20200329/f1340b113f9fa253cc0cef414c84a29d.jpg)(https://uploads.tapatalk-cdn.com/20200329/2939bc67cc00c08016ab3221d5b89b8d.jpg)(https://uploads.tapatalk-cdn.com/20200329/8b424370cbcd05bbd8e905438eb33beb.jpg)(https://uploads.tapatalk-cdn.com/20200329/154fd21675c8e3178ce79300f3282186.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 28, 2020, 09:56:53 PM
...(https://uploads.tapatalk-cdn.com/20200329/4f992ef36a6373d13fc81748a42787b0.jpg)(https://uploads.tapatalk-cdn.com/20200329/5afc28900a0101eae449253026767152.jpg)(https://uploads.tapatalk-cdn.com/20200329/9f926c72b961db8c1b827f172f521180.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 28, 2020, 09:57:58 PM
i think i’m going to be running these gauges in the dmax. let me know when you get it all together and/or how you like the module add ons.

Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 28, 2020, 10:10:45 PM
I gotta say, I'm pretty impressed with this setup. It has a pretty decent amount of adjustability, especially backlighting. All of the gauges have min and or max warning settings, and a buzzer with adjustable volume.

Right now I have the color set to white for daytime and green for night.(https://uploads.tapatalk-cdn.com/20200329/ff7e6f18207dc37a0741ef840f6287db.jpg)(https://uploads.tapatalk-cdn.com/20200329/0fd1261547d8072a2e03d1a6b4542232.jpg)
(https://uploads.tapatalk-cdn.com/20200329/8d85ea117c944f10dc017594aba7d16f.jpg)(https://uploads.tapatalk-cdn.com/20200329/1e6f68821b6e949df2b428db8ed9c2d0.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 28, 2020, 10:19:18 PM
yep.. getting those.

hahah
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 28, 2020, 10:21:54 PM
i think i’m going to be running these gauges in the dmax. let me know when you get it all together and/or how you like the module add ons.
I didn't enjoy trying to stuff that much wiring in the dash, and it's too bad all of those add-ons weren't integrated into the cluster, but I understand why.
Also the Bluetooth is slow, and only works once you manually put the cluster in setup mode with a corded switch you have to mount to the dash.
I do like how you program the speedo, by measuring a mile (auto mode) or using GPS (manual mode) and you have to do that within the first 100 miles or it locks you out (I think). Easy.
...and it gives preset options for the fuel sender resistance for each of the different years for gm, and Ford's, etc.
 It's pretty trick imo.

.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 28, 2020, 10:24:49 PM
i think i’m going to be running these gauges in the dmax. let me know when you get it all together and/or how you like the module add ons.
I didn't enjoy trying to stuff that much wiring in the dash, and it's too bad all of those add-ons weren't integrated into the cluster, but I understand why.
Also the Bluetooth is slow, and only works once you manually put the cluster in setup mode with a corded switch you have to mount to the dash.
I do like how you program the speedo, by measuring a mile (auto mode) or using GPS (manual mode) and you have to do that within the first 100 miles or it locks you out (I think). Easy.
...and it gives preset options for the fuel sender resistance for each of the different years for gm, and Ford's, etc.
 It's pretty trick imo.

.

hot damn. that’s what i’m talking about.

i thought it was slick that they have an option for plugging in to the OBDII for the LBZ.. but with all the add ons and options.. i’m more than sold
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 28, 2020, 10:27:47 PM
Last chore for the day was changing out the faded headlights. These were 70 bucks on Amazon with over 6k great reviews.(https://uploads.tapatalk-cdn.com/20200329/df6d5c4385949d21324b82fa1aaae918.jpg)(https://uploads.tapatalk-cdn.com/20200329/44ded81ed7d90d911ba1d561b2e386a9.jpg)(https://uploads.tapatalk-cdn.com/20200329/13d2f528bad5c04811c90e4748957933.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 28, 2020, 10:29:09 PM
i think i’m going to be running these gauges in the dmax. let me know when you get it all together and/or how you like the module add ons.
I didn't enjoy trying to stuff that much wiring in the dash, and it's too bad all of those add-ons weren't integrated into the cluster, but I understand why.
Also the Bluetooth is slow, and only works once you manually put the cluster in setup mode with a corded switch you have to mount to the dash.
I do like how you program the speedo, by measuring a mile (auto mode) or using GPS (manual mode) and you have to do that within the first 100 miles or it locks you out (I think). Easy.
...and it gives preset options for the fuel sender resistance for each of the different years for gm, and Ford's, etc.
 It's pretty trick imo.

.

hot damn. that’s what i’m talking about.

i thought it was slick that they have an option for plugging in to the OBDII for the LBZ.. but with all the add ons and options.. i’m more than sold
Didn't you help Turner install some of these? I don't remember looking at them but thought they were Dakota.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: swbhobie16 on March 29, 2020, 08:09:21 AM
no sir. they were a 4 in 1 4.5” gauge and a 2 in 1 4.5” with 4 single 2 1/16” digital gauges off to the side. the 4 in 1 was oil pressure, water temp, fuel and volts (i believe) and the 2 in 1 was speedo and tach (think reproduction 50s model chevy truck gauges) that each had their own comm wire from sensors. same with the digital ones. they were boost, EGT and trans temp. might have had another over there too. drawing a blank at the moment
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on March 29, 2020, 08:13:20 AM
Looks really slick Ken.  Now paint that steering column


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 29, 2020, 10:44:44 AM
Looks really slick Ken.  Now paint that steering column


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Quit giving me more work!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: Flyin6 on March 29, 2020, 06:56:34 PM
I like that gage cluster!

Me wants a square bodee!
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 29, 2020, 07:53:24 PM
I like that gage cluster!

Me wants a square bodee!
Do it! You don't have anything else to do, right?
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on March 30, 2020, 10:37:18 PM
Had a problem with the speedometer after driving about 3 miles.
I took the sensor off of the transfer case and found something less than perfect. They used a piece cut off of the end of a speedometer cable, just shoved into the sensor...no glue or anything.
Now it's epoxied and works again.
Pretty shoddy considering how nice this system looks. Hopefully the last issue.(https://uploads.tapatalk-cdn.com/20200331/d9160b4d51000dd8e3e7fe470a581d8c.jpg)(https://uploads.tapatalk-cdn.com/20200331/304792e1a7e7c4d03408a8ddc64d463c.jpg)(https://uploads.tapatalk-cdn.com/20200331/6b1cb16f8cdcdd01542737514fb99b44.jpg)(https://uploads.tapatalk-cdn.com/20200331/bf302a96187acd5a0716bbf70218f871.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: wyorunner on April 02, 2020, 02:32:00 AM
Had a problem with the speedometer after driving about 3 miles.
I took the sensor off of the transfer case and found something less than perfect. They used a piece cut off of the end of a speedometer cable, just shoved into the sensor...no glue or anything.
Now it's epoxied and works again.
Pretty shoddy considering how nice this system looks. Hopefully the last issue.(https://uploads.tapatalk-cdn.com/20200331/d9160b4d51000dd8e3e7fe470a581d8c.jpg)(https://uploads.tapatalk-cdn.com/20200331/304792e1a7e7c4d03408a8ddc64d463c.jpg)(https://uploads.tapatalk-cdn.com/20200331/6b1cb16f8cdcdd01542737514fb99b44.jpg)(https://uploads.tapatalk-cdn.com/20200331/bf302a96187acd5a0716bbf70218f871.jpg)

Interesting! My gauges were from auto meter not Dakota... for a couple reasons, but first... my speedo cable has a small piece like this that goes between the sensor in the T case and the cable, but it is just a piece of steel not cable, so a small plus.

Now, Dakota does not serve dodge much (nor does anybody for that matter) so I opted to get something that we could make work. SWBhobie actually made the dash plate from a piece of aluminum stock since of course there is no factory option for that truck. It has five physical gauges, two that are 3 3/8” one has the speedo and tach, the other has oil pressure, water temp, fuel gauge, volts, then we have three 2 1/16” gauges; boost, egt, trans temp. So in all, there’s a pile of wires going every which where behind the dash.

You’re more than welcome to go get the truck from storage if you’d like
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on April 02, 2020, 10:11:21 AM
 :popcorn:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: America.Mike on April 02, 2020, 10:20:23 AM
Very nice rig. Keep up the good work. I need to get my butt updating my build thread lol


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on April 02, 2020, 09:07:51 PM
Quiet Shawn adults are talking.

Dunno why I thought you had Dakota Wyo. Possibly too much whiskey.

Thanks Mike... and yes you do!! Haha
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on April 02, 2020, 09:38:30 PM
 :popcorn:  :popcorn:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on April 03, 2020, 09:18:45 PM
Just for Charles:

Also cleaned up the grill and headlight surrounds.(https://uploads.tapatalk-cdn.com/20200404/4fde32a986481945e9936e223545b9ea.jpg)(https://uploads.tapatalk-cdn.com/20200404/c24ed8ebbe6d405969f3bc23cdb83820.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on April 03, 2020, 09:32:28 PM
Just for Charles:

Also cleaned up the grill and headlight surrounds.(https://uploads.tapatalk-cdn.com/20200404/4fde32a986481945e9936e223545b9ea.jpg)(https://uploads.tapatalk-cdn.com/20200404/c24ed8ebbe6d405969f3bc23cdb83820.jpg)
Cratered to peer pressure


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on April 03, 2020, 10:30:54 PM
Well, while you’re at it where’s the 60 front?  :popcorn:
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on April 03, 2020, 11:45:34 PM
It's on the slab with the cover off letting the rust breath. :(
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on April 03, 2020, 11:54:42 PM
It's on the slab with the cover off letting the rust breath. :(

 :huh: Must be an Arizona thing.....
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: cruizng on April 04, 2020, 05:21:16 PM
Nice looking project.


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on April 04, 2020, 07:56:31 PM
Thanks Mike.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on April 20, 2020, 09:06:04 PM
Might as well continue this thread.

I've been saving a Dana 60, out of a dually, for this truck for about 14 years, assuming it was in good shape. It's not, and I'm not going to rebuilt it right now.

...but I will steal the 1-1/4" sway bar off of it to replace my smaller one, using poly bushings. Also replaced all the shocks, and front leaf spring bushings.

Just trying to get this thing to ride better. It's always been stupid rough.(https://uploads.tapatalk-cdn.com/20200421/9ac5954090ec28c99e3f5094ef16b865.jpg)(https://uploads.tapatalk-cdn.com/20200421/4480ee5dcde85c40ac73ca354f8082f5.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: stlaser on April 20, 2020, 09:21:40 PM
Tear the leaf packs apart and graphite paint them all separately and reinstall
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on April 20, 2020, 10:49:14 PM
Very nice, need SB upgrades on all my rides.

Like the green dash lights and hood. I had a low profile FG hood on my 77, wonder if that would fit the cummings though.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on April 21, 2020, 07:43:42 AM
Stiffer away bar. Yeah that’ll make it ride better....smh


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on April 21, 2020, 09:47:09 AM
Tear the leaf packs apart and graphite paint them all separately and reinstall
That's the next step. The rear ones are horrendous. Driving around with a spare for the 5 ton  at the moment.

Charles, the Cummins was making the front sloppy (worse than before). Main problem is out back....I should've specified.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: JR on April 21, 2020, 03:37:57 PM
I used to keep 4 sand bags in mine until I mounted a utility box and spare right on the rear, 40 gal tank heled to.
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: TexasRedNeck on April 21, 2020, 09:05:04 PM
Ken, have you considered soft rear springs and air bags?


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Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on April 21, 2020, 09:38:55 PM
I have bags already, and I'm considering putting some 1/2 ton springs in, or the graphite route, or putting shims between the leaves, like the newer trucks have.
I don't really want to change them because I know what kind of load they are capable of handling, compared to my '12 GMC ...
... I've hauled about 7k in the bed multiple times, without bags, back in the day (truck weighed 5600 pre-cummins)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on May 21, 2020, 12:37:12 PM
In the name of transparency, I have to mention the issue I had with the transmission.
Driving home a couple weeks ago it stuck in 5th, then neutral.
So the transmission came back out.(https://uploads.tapatalk-cdn.com/20200521/1500627c55779b491b5d3d4d0ef986bb.jpg)
Title: Re: 12v Cummins Swap/'73 GMC 2500
Post by: KensAuto on May 21, 2020, 12:43:21 PM
Of course, it worked fine on the bench, but eventually found a problem with the shift slider detent "shoes" on the countershaft 5th gear. They looked fine but would hang up under certain conditions, like shifting slowly.

I replaced that gear because of some wear where the shoes fit, the fork, and the slider. Feels much better now... just have to make time to reinstall.(https://uploads.tapatalk-cdn.com/20200521/5a894c5159d405a503e9d2ab8f079b12.jpg)(https://uploads.tapatalk-cdn.com/20200521/7009c7e11314356df29ce095940b8593.jpg)(https://uploads.tapatalk-cdn.com/20200521/72a6a161da9592a249f7b48423373dda.jpg)(https://uploads.tapatalk-cdn.com/20200521/f545a87d156af67d6a6133ee27b8adf6.jpg)
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