I have an 89 RS and i need to know what type of rear I have is it a 10 bolt? Also will a 12 bolt posi work?
Thanks

 

10 unless soemoen swapped in a 9 bolt, coult the bolts to be sure. after market 12 bolt will work as long as it's made for a thirdgen f body.

 

Count the number of bolts on the rear cover. Stock F-bodies usually had a 7.5-inch 10-bolt rear. Some had a Borg Warner 9-bolt rear. Do not rely on housing codes to identify what is in the rear, since most ratios have been changed and the rear can be converted from open to posi with a replacement center section. If you need anything, please email us at houser@rearman.com .