Gears & Axles - axle choice

Hey guys I'm getting ready to pick up a rear end soon and decided to go 12bolt. I plan on tracking the car a lot and launching on the street, what would be better the 31 or the 33 spline axles? Thanks for the help!

M6 or A4 trans?

Sorry M6 02 ss full bolt on ls6heads ms3cam 305/35/18 nitto 555r's

33 is better than 31 but be prepared for some gear noise from what I've read (M6 & 12-bolt).

Unless you're getting a smoking deal on a known good used 12 bolt I do not suggest using a 12 bolt with a M6 and hard launches...

Really? So 9inch is the better option I'm assuming

9" or S60.