I know that the stock rear end that came on our cars are weak, but what is weak? The spider gears? The Axles? The Ring and pinion? Or is the whole thing just crap? Thanks.

Paul.

 

Check out this site.
http://www.ws6transam.org/10bolt.html

Most all the 7.5 inch toasted diffs have ring and pinion problems(at least the ones that didn't get run out of fluid). Under 350hp. on street tires should last a pretty long time. 400hp and you hook-up good--probably on borrowed time.