New Member! Need advice on an 1953GMC/S-15 swap!

[53GMC]

Hello everyone! I am new to the site and am very interested in doing a swap on my 1953 GMC 100 to a 1989 GMC s-15.

I need any and all help on this! any little hints, advice, etc. would be most appreciated.

The S-15 is an extended cab, V6. It has a really good motor and tranny in it that i will be using....the questions come in the lining up of the cab and where to weld the cab support brackets, things like that....I saw the diagram on this site of how to make the brackets and i will be using that for the bed mounting, but where exaclty to mount them so that they line up is unknown to me.....

Like i said any and all advice is EXTREMELY WELCOME!! I have only begun taking fenders and what not off of my old truck but need any advice you can get me before i go too far! Thank you all!

53 GMC

[britnjc]

Well there are a few questions? Is your 50 a long bed or short bed. If it is a short bed the 89 s15 extended cab is to long and the fram will have to be shortened. A regular cab long wheel base S10 S15 is what makes this swap easy. Yours can be used just some frame work will have to be done. As far as where to mount everything, the easiest would be just put your 50 on the frame and get it situated and lined up on wooden blocks then you can see where your brackets need to be welded. As far as what I did I used the AD engineering kit and it gave me measurement where to mount everything but it will vary from different types of kits.

[53GMC]

thank you brittnjc....actually that was one of my questions about the frame....i measured the wheel base of both the s15 and the s10 and it matched perfectly

so that leaves me puzzled because the bed on my 1953 GMC is a shrotbed and it matches up.... what do you think britnjc? could it be something im not thinking of?

[mr48chev]

Search the threads here, there is plenty of info and discussion on the subject.

One of the members has generously shared his design (s) for the cab mounts so that you can either make your own or have a local metal shop make them at a lot lower expense than buying the kits.

I'm not a huge fan simply because of the need for thick spacers on the front hubs to run most wheels and keep them out far enough in the wheel wells to look proper.

[britnjc]

i believe the wheel base of a 50 short bed is 117" and the wheel base of a regular cab long wheel base is 118" which actually centers the wheel better in the wheel wells better than the factory 50 frame. here are the measurement of the s10 and s15 models. Regular cab short box - 108.3"
Regular cab long box - 117.9" Extended cab short box - 122.9"

What were the measurements you took on your s15

[53GMC]

on my 1953 GMC it was a wheelbase of 124" and on the S15 it was a wheelbase of 123"....so that leaves me puzzled because last week i looked at a regular cab short box s10 for sale and it had a wheelbase of 110" and found out that it was 14" short of the wheelbase of my 1953 GMC....so the extended cab, short box of the s15 matched better....what are your thoughts on that britnjc?

i appreciate your help very much!

[mr48chev]

You should be able to slip the rear axle back by redrilling the
locating holes in the spring pad on the axles similar to what we do when we put an open drive axle on the back with stock springs.

[britnjc]

How are you measuring wheel base. It goes from the center of one wheel to center of other. Those are really strange measurements. Look at www.AD-Engineering.com and there is a world of info there on this swap also. I might would invest in a new tape measure also.. Just Kidding