more cab swap questions

[BurnoutNova]

ok, so i was all set to buy a 3/4 ton 2wd cab for my 71 k10. the guy backed out, so now i need to look for another cab.

i might of found one, but its a 2wd 69 gmc cab.

ive been told the 1/2 ton 2wd cabs mount diffrently than 4x4 cabs. what will i need to do to make a 2wd cab fit on my 4x4 frame???

thanks, zach

[GMCPaul]

If the 2wd had a 4spd or a big block motor it will have a bolt in high hump center section and then after you install your 4X4 high hump there won't be any difference, if its not off a 4spd or big block truck it will have a low hump built into the floor and you will need to cut the low hump out and bolt in your high hump. That is the only difference between 2wd & 4wd cabs. What is different is the mounting cushions you place under the cab when installing it 4wd & 3/4 & 1 ton trucks all use a much taller cab mounting cushion than 2wd 1/2 tons.
GMCPaul

[LT4XTREME]

This is not the first time I've heard about the taller body bushings on the 4x4,3/4 ton, and 1 ton trucks, this makes since to me to raise the body for larger tires and because this is still being done on the new Chevy HD. The question I have is if the cab is raised then the bed would need to be raised to keep the body lines matched up and I've been under several of these trucks and have never noticed a spacer under the bed (I wasn't looking for them at the time)

[CPNE]

Originally Posted by LT4XTREME

This is not the first time I've heard about the taller body bushings on the 4x4,3/4 ton, and 1 ton trucks, this makes since to me to raise the body for larger tires and because this is still being done on the new Chevy HD. The question I have is if the cab is raised then the bed would need to be raised to keep the body lines matched up and I've been under several of these trucks and have never noticed a spacer under the bed (I wasn't looking for them at the time)

The taller mounts are compensated for by lowering the bracket on the frame. On a 2wd 1/2 ton the rear cab mount bracket is even with the top frame rail. On 3/4 tons and 4x4's, it is positioned below the top of the top frame rail. Hence no need for bed or front clip shimming.

[Mudder]

Seems like it would be easier to just shim the bed and front clip, than to change the cab mounts.

[LT4XTREME]

I guess that would put the screws to cutting down a lwb 3/4 ton frame to make a swb 1/2 ton frame unless you used the 3/4 ton body bushings or changed the frame brackets. (sorry to hijack the thread)

[CPNE]

Originally Posted by LT4XTREME

I guess that would put the screws to cutting down a lwb 3/4 ton frame to make a swb 1/2 ton frame unless you used the 3/4 ton body bushings or changed the frame brackets. (sorry to hijack the thread)

Yes but if you have the skill to cut down a frame, the cab mount issue should be a no-brainer.

[JIMs70GMC]

I installed a 70 2wd 3/4 ton cab (low hump) on my 71 3/4 4wd. I used the bolt on hump as a template and cut the low hump out and used self tapping bolts. Fit perfect. I replaced my bushings w/ poly bushings at the same time.