4x4 axle swaps?

[old Chevy guy]

I was wondering if I could swap 3/4 ton axels from a 73 to 80 something chevy truck to my 70 k10 the measurements look good,the only thing I see is the newer bigger axels have front sway bar and my truck does not. Has any one ever done this ? what do you think?

[Livrat]

The front end will bolt right in.. You will have to make mounts for the sway bar to attach it to the frame..
The rear end will need the spring perches moved and one shock mount relocated to the front side of the axle

[old Chevy guy]

Do you mean the perches on the axle? if so Why? I thought When I measured that the springs on the trucks were the same distance on center. Also could the sway bar be left off?

[Livrat]

Hmmm.. I could be wrong but it thought when I measured a 1976 1/2ton 4X4 12 bolt I had the rear perches were an inch wider.. Maybe the 3/4 tons are different??

Anyone else have any direct info??

Yes you can leave the sway bar off.. But it does improve the handling greatly

[old Chevy guy]

Thanks for the replys I have a 70 k10 and am not sure what to do with it.I have other trucks all HD and thought about beefing this one up a bit as I dont have a road worthy 4x4 .I have a diffrent project truck someone else gave up on and Im pretty sure the 4x4 frame is a 76 it has dana axles and lock out hubs. also I have a diffrent frame for parts for the same given up project that I believe is an 80 both are 3/4 ton the latter also has dana but not lockout hubs I will check the measurements again.

[jerry moss]

spring perches will need to be moved in about an inch on both sides of the rear axle if its a 3/4 ton, i have 14 bolts under both my 72s and i had to move the perches on both, one shock mount also. i've heard that some one tons in the 73-up vintage have the same width on the perches but ive never measured one myself.
the front is a direct bolt in.

[jimi121v]

I used the rear spring and shackle hangers off the 76 3/4ton that the axels came from. The frame rails are the same distance apart, and the hangers are wider. They are also much beefier than the stock ones on my 72 c10. I bolted them to the frame with 7/16" grade-8 bolts. I used the stock 76 3/4 ton springs also, so I now have 56" rear springs, and it gave me about 3" of lift with no blocks. It turned out great, and I just had to move the one shock mount.

In the front I used the 76 front cross member with all the sway bar hardware. It doesn't fit the old mounting holes, but I just put the whole thing all together, clamped it in the frame, and drilled new holes. It sits just a tad foreword of where the stock one was. The whole project was fairly easy, even though I had to grind and drill all the rivets. I could have used a cutting torch, but I didn't want to bugger up the holes. All in all not too difficult though.

Jimi

[SUPERTRUCKER!!!]

3/4 ton 73 and newer rear axles have wider spring perches. the one ton rear ends are the same as the 67-72. i have a 72 chevy i am building and a set of 3/4 axles with the wider perches. my recently purchased 77 one ton has the narrower perches and would bolt right in.

[old Chevy guy]

Thanks guys this helps, what about the frame on k10 vs k20 ? Ilooked at a couple of 4x4 s before [70 era] and the frame seemed bigger that is to say the frame rail was taller. The trucks were pretty beat so it wasent clear if they were k20 or mabey k30. the frame on my k10 [70] lookes and measures up to my 72 custom deluxe c20 that has rear leafs. Is a k 20 heaveir than the k10 and c20 or only when you go to 30? I have a 72 GMC 3500 2 wheel drive parts truck and the frame on that is HD also.

[1969k10stepside]

K10,and K20 use the same frame.Just different rear axle,front hubs,some front diff. parts,and the springs.The 1 ton is when the frames got heavier duty.There was no factory 1 ton 4x4s from before the late 70s so any 1 ton 4wd you seen would have been a swap from a person,or a Napco Conversion

[old Chevy guy]

I thought the frames were the same.I rechecked the measurments today and you were all right the perches need to move in about an inch each . I noticed a difference in the distance between the backing plates on the rear axel. Any coments on that ?