Specifically a 2007 LT? For both front and rear. I don't know what size rotor to order, I'm given 3 different sizes at RockAuto. Also, do the rear calipers need turned back into the piston or are just compressed with a clamp like older calipers? Thanks.

It depends on what RPO code your car has for the brakes. There is two options for the front brakes which are J41/J67 (10.866 in diameter), or RPO code JL9 (11.653 in diameter). RPO codes should be listed on a sticker in the glove box or PM me your VIN and I can look up you build list.

The rear brake rotor is 10.630 inch diameter, and that is the only one listed for the rear. The rear caliper pistons need to be turned to push them back in.