1973 -1980 Cab Swap Question
 

My cab on my 75 GMC is rusted bad !!! I mean bad !! Is there a difference in a 2 wheel drive cab and a 4x4 cab other than maybe the center hump ... In which I believe some have a bolt on center hump .. any help is appreciated !!

Re: 1973 -1980 Cab Swap Question
 

not to my knowledge, but i don't know much. i did a cab swap from a 79 to a 74, both 2wd though. I'd imagine aside from the larger center hump, everything else will bolt up.

Re: 1973 -1980 Cab Swap Question
 

Watch the Vin location. 78 and down on door pillar post 79 to 87 on dash. But physically it will all bolt up.

Re: 1973 -1980 Cab Swap Question
 

the thing you have to do on the newer cabs ( 81-87) is change over the wiper transmission and remove the cowl piece that is too tall for the older hood. The vin tag is the other issue. Use the chassis correct mounting kit and other than that youre good to go

Re: 1973 -1980 Cab Swap Question
 

The wiper switch moves around on the dash as well. 73-4, 75-83, and 84-up are different.

Re: 1973 -1980 Cab Swap Question
 

You can use a 2wd cab on a 4x4 if you use a 2" body lift. That way you don't have to cut such a big hole in your new rust free cab floor.

Re: 1973 -1980 Cab Swap Question
 

The 4x4 cab will have a hump for the transfer case too. I put a 79 2wd cab on my 78 4x and removed the transfer case hump and the bolt in dog hose from the 78. Real easy job. Just cut along the lines on the 2wd drive cab and spot weld the 4x pieces in place. I drilled holes and welded nuts on the underside for the dog house so it would be removable. I used square nuts so it would look factory.

Re: 1973 -1980 Cab Swap Question
 

If you wouldn't mind, could you post a few more pics of this swap? This winter I am going to try and do the same thing. I am switching the hump from a 4x 79 to a 2wd 78 cab. Thanks!

Re: 1973 -1980 Cab Swap Question
 

I could show you photos, 2wd cab put on 73 4x4. Only difference is cutting the whole for the shifter.

Can you use a 89 wire harness hooked up to a 86 engine? No it's not a v8.