I have an '81 Elcamino, and a "73 Nova, both with 10 bolts. I bought a rear end out of a '91 Z28, (10 bolt PBR with 3.73s). I want to swap the posi, gears, and the discs into the Elcamino, or if not, the Nova. Would this be possible?

 

Your 91 will be a 7-5/8" 10 bolt. The 81 and 73 should be 8.5" 10 bolts. Nothing is interchangable between them.

The 81 "might" be a 7-1/2" which is interchangable with the 7-5/8" however if it is, it will be a 26 spline carrier and won't be compatable with the 28 spline posi from the 91. You would need 28 spline axles.

 

I was told ten bolts were 8.5", but I forgot about the spline issue.
What about the brakes? Will they fit?

 

There are actually 3 different GM 10 bolt diffs. The strongest is the 8.5". They produced an 8.2" for a while but it had problems and was never really popular. By the time the third gens came out, they only made the 7-1/2" but upgraded it to 7-5/8" around 1986. GM switched from 26 to 28 spline axles in these tiny diffs in 1990.

Chances are the brakes won't be compatable. Normally the backing plate/caliper mount has a different bolt pattern to attach to the flange on the end of the axle tube between disk and drum brakes.

Anything can be adapted if you have enough time and energy but don't expect swaps like this to be a direct bolt in.

 

Well I guess if I have to I'll just have to weld brakets on to the Camaro rear to make it fit my Elcamino.