Here is my problem. I have a 98 camaro z28 w/ A4 tranny. I have factory 2:73 gears in the rear. I wanted to change them to either 3:23 or 3:73 gears. I was told that I have a series 2 differential and i need a series three. Now my problem is the number of splines in my rear. How can I find out how many splines are in the rear. Also i have a limited slip and i live in NY (SNOW). I was told to change to a posi. Can anyone help me out with this. Thanx!!!

Limited slip is the same as a posi, you most likley have a Torsen limited slip in your car, which is pretty good (as far as our weak 10 bolts go). I am pretty sure you can go to a 3.73 in series two carrier, you just need a ring gear spacer IIRC. The axel splines would be the same on either carrier or with either gear.