If you are going to have 500+ hp i would go with 3.0 & 4.56 or 3.8 & 3.73. We went from 4.56 to 4.10 in ANGER MANAGEMENT(Nick Cooper) with a 3.8 because he was running out of gear.it seemed to help a little but, now he wishes we would of used 3.73. I would try to keep your final ratio somewhere...