My 87 Trans Am has a 2.77 axle ratio. I'm hearing that this is a 9-Bolt carrier (Series 2). I'm planning on ordering a 3.73 gear set, but I don't see anything on Jegs about a 9-Bolt. I see the gear set for the Series 2 carrier and Series 3 carrier. It states that Series 2 is 3.08 and lower carrier, and Series 3 is 3.23 and higer carrier. So, do i have a 9 or 10 bolt carrier?!!

Crawl under the car and count the bolts. Should you have a 9-bolt, finding parts may be difficult. Check the following link for a ton of info:

https://www.thirdgen.org/forums/faq-...now-about.html

JamesC

2:77 gear ratio is from a BW 9-bolt rear and you will find very few replacement parts. Most everything from a Autoparts suppliers are for 10-bolts and the part are NOT interchangeable. Example: 9-bolt ring gear 7.750 dia vs 10-bolt ring gear 7.5/.625 dia.

Right, I know they're not interchangeable. Will an aftermarket 10-bolt carrier work with the BW housing?

One big NO... .nothing and I mean nothing is interchanable.