I just put a 62" wide rear differential from an 85 Caprice under mine, it was a 10 bolt posi with 3.42 gearing and I was excited to have it. I spent several hours with a 4" angle grinder cutting off the coil spring mounts, spring mounts and the 'ears' on the pumpkin for the locator bars. Then I tack welded the new spring perches in place and put it under the truck with the rearched springs. It was an exciting day!

Unfortunately, when I bolted my the 235/60R15 mounted on 5 on 4 3/4" stock gm steel rims the inside of the tires rubbed against the frame. That's how I learned the backspacing on the older rims is different from the newer rims and really needs to be thought about before you go out and get that axel.

My story ends happily though... A friend traded me his 65" wide 12 bolt posi with 3.72 for my 10 Bolt straight across. The 65" axel should be okay with that extra 1 1/2" on either side.

If you are at the boneyard looking for axels, don't overlook the cadillacs, sedans and station wagons, there were lots of posi's in those and the width is in the range you might be looking for. The only diffence between the 10 bolt gm axels is the ring and pinion diameter. Some had smaller ring gears than others. The smaller ones might fail easier and were produced less so it might be harder to find parts if you need bearings/seals/shims/new gears.

'51 Chevy 1/2 ton w/'62 261, HEI, offy, fentons, dual carter/webbers, t-5 & 12 bolt posi