which pinion for savage?

hey guys i bought the 16t pinion from rcmonsters and was running it with 49t spur on my feigao8xl..i cant keep the wheels on the ground..what pinion do i need in order to reduce the wheely a bit?do i need to go up on pinion or spur?i tried 16\52 and the more i get massive wheelies.i want to hit the throttle and see this truck in full speed ..i never broke anything on my savage but with the 16\52 i bent the rollbar on the 1st time i ran it..