Well since my stock posi unit is apparently going for a dump, what do the seasoned autoxers suggest I replace it with? Torsen? Auburn? Locker?

Keep in mind I do some street driving but also do alot of autoxing and lapping days at various road courses.

I currently have a 10-bolt 26-spline assembly with 3.73 gears, but was thinking of maybe upgrading the axles to 28-spline (or higher if possible) since I have to change the posi.

 

I have an Auburn in my IROC with 28 spline axles and I love it. It's been really good to me while doing autocross. Another thing to think about is going to a 4th gen rear, it's a pretty easy swap to do, and then you'd have the 28 spline axles. This could also be a good opportunity to get disks on the rear (if you havent already).

 

I went from a non-posi, 26 spline, drum brake rear-end to a torsen, 28 spline, PBR disc rear-end. I haven't taken it auto-xing yet since the changeover, but I plan to next season. From what I can tell on backroads and after a little "parking lot" fun it seems like it's a HUGE improvement.

 

Torsen T2R...seems like the favored unit.