74 2WD C20 Body swap onto 87 K20 4x4 frame and running gear?

[Heavy1/2]

To make a long story short I've found a 1987 GMC 2500 4x4 for a very decent price... The truck is complete 350/400 NP208. I want to swap the cab and core support from of my 74 C20 (2WD) onto the 87 frame and running gear.

I know I'll have to modify the front portion of the 87 frame to fit the 74 core support, and remove the 2WD tranny hump... I was just wondering if there would be any other foreseeable porblems?

I read somewhere that I might run into clearance problems trying to fit the NP208 under the 74 cab... Can anyone confirm this? I'm sure a small body lift would help?

Cheers!

[J Knight]

I dont know about the 4wd stuff but the cab will bolt to frame mounts you just have to use 81-87 cab bushings. The frame brackets for the core support only need to be moved about 3/4in.

[Captkaos]

I have never moved the core support mounts on the ones I have swapped.
If you don't use a body lift, you will need the trans tunnel from the original as the 2WD hump won't work. Is the 87 cab that bad?

[Heavy1/2]

Originally Posted by J Knight

I dont know about the 4wd stuff but the cab will bolt to frame mounts you just have to use 81-87 cab bushings. The frame brackets for the core support only need to be moved about 3/4in.

Thanks for the info! Every bit of advice helps. I'm sure it's going to be fairly straightforward. I was basically curious whether someone has done a similar swap . Good to know I can get away with just moving the factory rad support brackets a touch.

[Heavy1/2]

Originally Posted by Captkaos

I have never moved the core support mounts on the ones I have swapped.
If you don't use a body lift, you will need the trans tunnel from the original as the 2WD hump won't work. Is the 87 cab that bad?

I knew I'd have to modify the trans tunnel. The cab from the 87 is in much worse shape than the Cab on my 74... The cab on the 87 will need new rockers and cab corners at the very least, I haven't had a chance to inspect the floor yet.

Thought it would be neat to swap the 74 body onto a platform with slightly more modern components. I thought about modifying the frame on my C20 and putting in longer/larger springs front and rear, shackle reversal etc. etc.

I paid very little for the 87. I would have spent much more time and money trying to modify the frame on my C20.