4.10's
 

what is the best brand and do i have to calibrate anything once they are in?

Best brand is arguable.

Most people just reccomend going with a brand name like Richmond, Strange, etc.

Obviously your spedometer will be off after changing gears.

My buddy in his 00 SS put richmond 4.10's in his and I kid you not, 3 weeks later he heard a grinding coming from the diff. and when he took it apart there were 5 splines broken off the pinion gear. It is very possible that he just had a defective gear but he never launched his car at all. Richmond refused to replace them also.

I have richmond 410 with 50 miles on them. $80+shipping

i have motive gears and am very pleased.

i have GM 4.10s and they are great.

I also have Motive 4.10s. they make a little noise, but not nearly as much as my richmond 3.73s did in my LT1. and yes you will have to recalibrate your speedo.

GM gears is the best way to go!

noise
 

ive always used richmond. the name has nothing to do with noise its the tech installing the gear.no gear should make noise if set up correctly.

4.10 Motive with an Eaton posi.. 38K miles on the clock and they make no more noise than the day they were installed.

4.10's wake up an M6 like a stall wakes up and A4!