1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

I've been meaning to start this thread for quite a while but I've been so busy with the build I never found the time. The project initially began to return my fathers work truck to a fun driver, and then spiraled out of control to the complete custom build it is today.

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1235647
Attachment 1235647
More tear down and build pics to follow tonight

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

I'm signing up to see the workings of this one! Should be sweet!

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Initially I acquired the 2003 donor just for the Duramax engine and Allison transmission that I intended to install into a donor k20 frame. But once I inspected the 2003 running gear and frame I was pleased to find that there was almost no damage. New motor mounts, transmission mounts, a couple batteries, and a few quarts of oil was all it needed. It started on the second try..... Hmmmmmm time for a quick test drive to check the rest of the running gear before tear down.

I can figure out how to build a truck from the ground up but not how to attach a video clip into a thread......:dum:

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Because it is so boring and I am using 3 donors I'll fast forward through the disassembly process.
Attachment 1235836
Lots and lots of labeling wires, and tagging / location of parts for possible future use in the 70 body.
Attachment 1235836
Thankfully I took the time to do this. Instead of making the engine stand alone I decided to use the complete 2003 wiring harness and computers to maintain all of the new function in the 1970 to include the airbags.
Attachment 1235836

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

I've noticed that each time I upload a pic it gives them all the same file name and attaches the last photo uploaded for all photos.
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Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Looking good. Did you have to shorten your frame? What color are you going to paint it? Keep it up.

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

I had to move the rear axle forward 7 1/2" forward and the gas tank 4 1/2". Trim about 3" off the rear of the frame. I started this thread late so I have lots more to post just not enough time. I'll try to post more pics this weekend. Almost all Fab is done and down to final body work. Trying to have it complete before end of July to drive it to Reno for Hot August Night show. Plan to paint it Blue and Silver but haven't settled on final paint scheme.

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244478
Relocating the rear axle forward about 7 1/2 "

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244479
Lots of cleaning to remove the original frame coating and fabrication of new cab mounts

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244480
More cleaning and engine internal inspections. Install ARP head studs.

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244481
Cleaning and Painting

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244483
More cleaning and painting

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244489
Internal inspection and installation of TRANSGO Shift kit to I prone 3rd-4th gear shifts

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244492
Again Cleaning and painting

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244494
Engine assembly

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244497
Paint frame and suspension components.
App paint on frame, engine, trans, transfer, and axle is POR 15. Let's hope it holds up as well as they claim.

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244498
Re seal rear axle, swap gears from 3:73 to 4:11 Clean and paint and all high capacity PPE Aluminum Diff cover.

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244499
Install transmission and transfer case. Also re install all suspension components with Energy Suspension urethane bushings, Pro Comp shocks?

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244691
Christmas came early. Banks full power pack with monster exhaust.

Re: 1970 C20 long bed Duramax, Allison, on a 2003 4x4 chassis
 

Attachment 1244983
Installed fuel tank MBRP 3" down pipe and 4" stainless monster exhaust