GMC C25 Crew Cab Converting to 4WD

[hayesperformanceplus]

Hey Everyone,

I know that the easiest way to convert to 4WD to a Body swap to a 4WD frame, BUT has anyone successfully converted a 3/4 ton 2WD Crew Cab (or Reg. Cab) to a 4WD using the 2WD Frame?

I have a complete 1980 3/4 ton 4wd donnor truck (Reg. Cab) I'm using.
And the Truck that I'm converting is a 1980 GMC 3/4 Ton Crew Cab.


All the info I can get will be great!!!

Thanks-a-million in advance....


David

[Mattman2010]

Check my crew cab build thread in my sig. I took a 85 C30 and am converting it to a k30. Basically the same thing just k30 parts vs what you would use to do a swap with k10/k20 parts. Read my thread and if you have any questions send me a PM Ill be happy to help or take some close up shots for you!


*Edit*
I just noticed that your k20 is a 1980 & your crew cab is a 1980, basically just cut the rivets off for the front body mounts/front spring mounts, mount them to the crew cab frame, will have to drill some more holes, but that is easy. You will need a 2" hole saw to cut for the spring hanger on the front end. As for the rear end, there is a difference between 4x and 2x spring hangers, so just cut the 2x spring hangers off and put the 4x spring hangers on. I did my swap with pre 81 parts but I found the correct parts now so that is why I was having trouble with my swap.

[b454rat]

I did this to my 89 crew. I used DIY4X B-52 kit for the front. It locates the front spring as well as the core support. Need to drill the 2' hole like Mattman said, also the 4 3/8" or whatever they are to bolt the swing shackle to the frame.

I did a poor man's shackle flip on the rear. I used 1/2-3/4 4wd rear spring front hangers, then 2wd hangers for the rear, used the stock springs on the back, for now.

The engine crossmember can be a pain. A stock one won't fit in the frame of the 2wd. I ended up using part of the 4wd mount. Not sure what it's called, but where the rubber mount bolts to. I trimmed it down then boxed it in. I plan on putting a Cummins in it, so did some horse trading on motor mounts and crossmember from Tennessee Diesel Conversions.

There is a lot of small stuff that needs to be addressed, any questions feel free to ask!!!!!

[madcow75]

Did it to a C30 had to cut down motor mount hangers 5/8" as my 1 ton frame section in the front was 5/8" smaller ( not as high) as 4x4 motor mount hangers. Drill lots of holes and lots of nuts and bolts. Have fun

[hayesperformanceplus]

b454rat

I would GREATLY appreciate your help!

By the way,

IF I could by fluke chance find a Crew Cab 4X4 frame, would it have to be a 73'-80' 3/4 ton frame? or which years work?

Thanks!

David

[hayesperformanceplus]

Mattman2010

I'd be very happy to get your help too on this....

The more help from members that HAVE did this conversion the better.

[b454rat]

Only diff in the frames over the years is I think the very front where the bumper goes on. I pretty sure that was it. But doesn't really matter what year, will have to be a 1 ton, tho supposedly GM did make a 3/4 ton 4wd crew cab.

[hayesperformanceplus]

Can the 73-80 bumper mount to the 81 and up front frame?

[Mattman2010]

Originally Posted by b454rat

Only diff in the frames over the years is I think the very front where the bumper goes on. I pretty sure that was it. But doesn't really matter what year, will have to be a 1 ton, tho supposedly GM did make a 3/4 ton 4wd crew cab.

Im pretty sure the only difference between a 1 ton and 3/4 ton 4x4 crew is the front axle. Either a D60, or D44.

Originally Posted by hayesperformanceplus

Can the 73-80 bumper mount to the 81 and up front frame?

Ive seen some people cut the front section off of a 73-80 frame and weld them to 81 up frames to get it to work. Not sure if they work any other way.