Looking art changing the gears in my (wifes) 96, What do I neet to know..?..carrier size?...existing size..it it had drim brakes..anybody have any opinions..?

 

what gear does it have now , and what are you wanting to go to? It might be be in your best interest to just get a used rearend from a Z and transplant it. thats what im planning on doing

 

call these guys http://gearsareus.com thats what i did
but your right, you will need to know what series she has right now.

 

auto v6 is normally 3.08's
manual is normally 3.23's
If you still aren't sure look for these codes in your glove box or door

GU80 = posi
GU2 = 2.73(only V8s)
GU4 = 3.08
GU5 = 3.23
GU6 = 3.42(came with Y87 option)

2.73, 3.08 are a series 2 carrier 3.23 all the way up are a series 3. If you do changed the gears then get the posi if you don't already have it! Or if you have drum look for a rear from a Z car and you can get a 3.42 gear, disk breaks and posi that have been factory set. I think most M6 cars came with 3.42's...but correct me if I am wrong