Ive used the same 2 servos, Futaba s9451 ( steering) and a s9351 ( throttle) in all of my cars for almost a year ( xb8tq, xx4,xxxcr, mf2, cl-1, Savage, 8t) . The only problem I had was a stripped gear in the 9451 as a result of a too tight servo saver on an 8t I got off here. The 9451 had no problem turning the wheels on my Savage ( ext. chassis, Losi 8t wheels) either.

I just picked up a JR 9000s and 9000t to try out. The S is lightning quick.