60 gmc to 65 c10

[schmittyjr]

I have a 65 C10 set up to be a pull truck with a Dana 60 8 lug rear with leaf springs welded on. I have a 60 GMC rear rolling frame with a Eaton HO32 with sway bars and coils. I want to get rid of the Dana and go back to 6 lug(no longer pulling). I know the sway bars are the same but how much trouble will it be to fit the complete rear and all accessaries on the 65. I know the shocks are mounted on the other side of the rear and panhead bar is also different. Thanks for the input

[markeb01]

I don't have the answers you need, but welcome to the forum.

[schmittyjr]

Thank you. Great forum, great people. Guy I bought the rolling frame from said it was a 66 and I didnt look close enough due to trying to get back home before dark. Looked right at first glance then noticed Eaton rear. 300 dollar lesson.

[markeb01]

I'll be surprised if it turns out to be a GMC. All the 1/2 ton 60-62 GMC's I've seen (including mine) came with Dana 44's.

Captainfab usually checks in later at night and knows a lot more about this stuff than I do. Hopefully he'll have the answer.

[schmittyjr]

VIN on the frame is N108750 XXXXX. Thats not to say thats the factory rear though. Numbers on the rear are MD1202 any idea to what ratio suppose to be in it. Its not in a location for me to lift it up and spin the tires. I read you cant make these posi trac if their not already, any thruth to that? Would I even be able to switch to 5 on 4.75 axles. Thanks

[losthope]

heres a thread on i.d.'s for trans,vins,axle,engines:
http://67-72chevytrucks.com/vboard/s...d.php?t=327764

it i.d.'s a MD axle as 3.90 ratio non posi for 1960,1961,1962

[schmittyjr]

Thanks losthope.

[Captainfab]

I'm not sure just what the determining factors were, but the GMC's were available with the Eaton HO32. The 3.90 gears were the most common in this differential. There are virtually no other gear sets available for these differentials, so you are basically stuck with the 3.90's. There used to be someone offering 3.38 gears for these, but I don't think they are available any longer. There just are not a lot of guys running this differential anymore, so there really isn't much in the way of aftermarket support for them. I don't know if any of the passenger drums would work to convert to 5 x 4.75. IMO I wouldn't waste my money on this differential when there are so many other options which have better aftermarket support.

[schmittyjr]

Thanks Captianfab, I found a 12 bolt today out of a 70 monte carlo with 410 posi. complete drum to drum so im picking it up this weekend. The purchase wasnt a total loss, I can use the trailing arms and springs to get it back to stock.