Hey everyone, I was wondering what types of rear axels would fit right into a third gen firebird(If any at all) I have stock 3.42's(Open) and want a Posi unit. Would it be easier to swap the entire rear axel or swap the diff? Thanks for any help or advice.

 

Any 82-2002 9 or 10 bolt will drop right in. Use the search feature to find the differences. It has been covered hundreds of times.

 

https://www.thirdgen.org/forums/tran...-10-bolts.html

 

Fourth gen diffs have the same weak 7.5/7.625" ring gear so they're no stronger than a third gen diff. The fourth gen diffs are probably easier to find since third gens are getting a little old for many junk yards to carry and they'll have better brake options.

If you want something stronger than the weak diff offered from the factory, it's unlikely you'll find anything in the junkyard unless you luck out and find a scrapped third gen with an aftermarket diff in it. Your only other option for something better is to buy an aftermarket diff designed to bolt right into a third gen such as a 9", 12 bolt or Dana 60. None are cheap.