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I have a 1972 Gmc 3/4 ton 350ci, 4bbl, 4spd with ONLY 18000 miles.(old farmers truck) I want to know if anyone has info on converting truck over to a 4x4. Can it be done without doing a frame swap? Any info or posts would really help. I'm not scared to read and learn, just need to be pointed in the right direction.

First off, WELCOME to the Stovebolt
Awesome site wit awesome people and trucks

Well, it CAN be done but you will need a 4x4 truck for all the pieces and parts to swap to your frame.(Cross-members for engine and trans, spring-hangers and springs, 4x4 front axle etc.)
I personally feel that it will be much easier and less labor involved to swap the 2x4 body onto the 4x4 frame.

I dont know that its even possible to convert a 2wd frame to 4wd. a 2wd frame has different mounting up front for the A-arms. I agree with Mechaniac that it would definately be easier to put your body onto a 4X4 frame.either way good luck

72 should still have the ridgid axle with leaf springs in front shouldn't it? Standard has Independent suspension and coil springs. Frames are diff on most x0overs in that area, then you have the transfer case mounting supports and the blocks or raised rear end to level it, and....and .....
Something that old if really nice should be left as is and enjoyed. I can see it now...half-way thru project some major problem, you get discouraged, give up, try to sell it as "package" and get 25% of value of the orig truck just to get rid of it!

Well, armed with that info, either swap the body or leave as is and enjoy

The floor under the seat might be different,I know on the 73-up they are and probably on the 67-72 also. The hump will be bigger to clear the transfercase,this swap might be more hassle than its worth.

My 72 3/4 4x4 has a 2wd cab on it :p
No clearance problems and it has stock height body bushings

Thanks for the replys guys. You all have great points. The reason for the interest is that the 72 3/4 ton its in alright shape. It was used for a farm truck. With only 18 000 miles on it, I know things are not sprung. I have a 78 3/4 ton 4x4 that was used, abused, then driven pretty hard. Has new T-case and front diff. Thought it would be sweet to make super truck out of 2 really great trucks. That is my next question. How much different is the newer frame. I don't think I could just do a body swap. Up here, it is hard to find older gm or chev 4x4s. I want to use what I have available. Thanks guys.

Hey Wiljon whereabouts in SK are you? I'm in school in Saskatoon right now, but come from near Lloydminster.

Well, what you have to do to make the 72 2wd into a 4x4 is to remove the front suspension and main cross-member. engine will have to come out as well. take the whole front axle, springs, spring mounts, cross-member out of the 4x4(you may have to fabricate a few things but it can be done. Then you will need to adapt/fabricate the T-case/tranny mount to fit into the 2wd. The rear end will most likely be a trailing-arm type suspension and it will need to be swapped as well(some had leaf-sprung rear suspension).
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All in all, I think it would be easier to adapt the 72 body on the 78 frame. It has been done before.

Jeff C, I'm an hour south of Regina. I guess I might just as well leave well enough alone 'til I can find a 72 4x4 for a body swap. I just need a auto trans for the 78 4x4. The housing got broke. Other guy was hard on it. Can you take a 2wd trans and swap parts like tail shaft, etc.. I like swaping parts. I like to tinker and learn. Thanks guys.

If the tail-housing got broke, you can either have it heli-arc welded or if you want to swap it, you can use the case from the other truck but you will have to remove all the internal parts from the 4x4 tranny and put them into the good case. The tail-shaft is really short on a 4x4 and the 2wd tranny tail-shaft will not work

Let me see if I understand. I can use the case from a 2wd. I believe the trans is cracked before tailshaft. Use internal parts and tailshaft from 4x4 and it will be all good. Both trans are Turbo400

Yes you can Will.

The case will be the same but you will have to use the 4x4 internal parts.
Might as well get a rebuild kit since you will have to completely dis-assemble it.

I have done it and vowed to never try it again. I swapped the running gear from a rusted out 72 3/4 ton 4x4 to a 69 1 ton Longhorn 4x2. It took over 100 hours of labor. I had to change the engine cross member, front body/ spring mounts, drive line and axles, front shackles and mounts (the hardest part). It was easiest to do with all the parts from the donor. I had to replace the front brake lines at $100 for the pair. I also had to modify the rear driveshaft since the donor was a 8 foot bed and the new truck was 8.5 foot bed. It was a unique truck but for the time and money I said I'd never try that again. I sold the truck when I joined the Air Force but have since bought a 66 GMC Factory 4x4. 67-72 4x4s are out there so I'd just find one if that is what you want. Watch E-bay and local want ads for a cheap one to come up. Since you have the 78 4x4 remember that the wheel bases are different. 67-72 wheel base is 127in for a long bed and 131 in for a 73-87 long bed. If you decide to go with your plan of the conversion you are welcome to write me and ask questions.