[Batman]

What tranny you have? If it a 5 Spd go with 4.10's, if it is an A4 I would stick with 3.73's. I'd get the eaton Posi and go for the gusto with 33 spline axles, if you are gonna do it may as well do it right instead of looking down the road and saying " Boy I wish I'd.....". For the extra price it is a little more piece of mind. I don't think it will make THAT much of a difference between 30 and 33 spline, but just what I would do. I have the 33 spline in my T/A and with over 400HP on tap and slicks not some much as a grumble from the back. Also spring for the aluminum diff cover, helps alot with cooling at the track. Good luck and sorry to hear about the 10 bolt!