I have a 91 RS, and want the basic gear upgrade. I want to upgrade to 3.42's.

 

I've got a set of 3:42 out of an 89 firebird in good shape. I bought them here on third gen but need money for engine repair. I'll take $50.00 shipped in the lower 48. Also can't do paypal.

 

Since you currenty have 2:73's then you have a 2 series carrier.

If you want to use 3:42's then you will have to buy after market 3:42s that fit a 2 series carrier or change your 2 series carrier to a 3 series carrier.

If I were you I'd do a search and read up on it.

 

I was going to put these in my 86 Z-28. I realized that it would require a .500" spacer which isn't all that expensive.

 

The ring gear spacer works well. I got one off ebay from "riversidegear"...about $50 bucks.