i run 2.73,,,with tremec trans,,,45 in 1st geat 80 in second 120 in third,,very nice,,il never use anything else,,,do the math before you choose a rear and u can choose when u want to shift,,,,so if u have 2.73 with lets say a 4th gear ratio of 1.00 u would be at 2150 rpm at 60mph with rouhgly...