The 71-72 8.5" 10-bolt is hard to beat.The parts are readily available,& affordable.They are just as strong as stock 12-bolt chevy parts,plus they have bolt-in axles,no c-clips.You can have a complete 71-72 8.5" 10-bolt done for less than a 12-bolt Chevy simply because the 12-bolt Chevy housings,posi or not,have a greater value,*& all of the Chevelle guys think it is a must to have one.There are a few more gear ratio choices with a 12-bolt,but there are enough for the 8.5" 10-bolt. The 8.5" 10-bolt,rebuilt,with the factory 28-spline axles,can handle a 3900lb big block car,going as fast as 11:50's.If it is something faster,I would recommend aftermarket 30-spline axles.I ran my 8.5 for many years behind my 507,going 10:80's,and it is now behind another big block car with a stick,& still holding up.
