According to Chevy High Performance magazine.
The GM 8.5 " 10 Bolt rear end is nearly as strong as a 12 bolt. The 12 bolt Ring gear diameter is 8.5" vs the 10 bolt 8.375". The pinion gear diameter is the same for both 10 & 12 Bolt rear ends. The 8.5" 10 Bolt rear end was nearly universally used in GM cars and trucks from 1971 -1996. So just look for a 8.5" 10 Bolt and most wrecking yards should be able to tell you which ones will fit your application. I put an Eaton Posi and 3.73 gears in my 1976 Monte Carlo and the rear end has been working well. Hope this helps.