i just checked my code numbers and i already have 4.10 gears. as far as tires i have 305/55/20 nitto terra grapplers on 20 x 10 wheels. i'm trying to stay away from turbos, too much underhood heat. don't like sts turbo too many potential problems.(and they told me 10,000.00 for the whole kit, and that was with me installing it)

 

what 10,000 thats insane pm me if your interested ill make you a good deal.