well i went overkill and put 4.88's and a posi lock...you will be alright w/ 4.56 gears i would put a locker in too and upgrade the axle shafts...whgat kind of rear axle you have?You will probably be good w/ buying the gears and everything to install them and a super35 for dana 35 kit(30 spline axles and a detroit locker)if you want some links i can get you some good prices i think