hi all i am a crawler guy but my daughter talked me into this little merv, i actually luv it, super fun,i have it in beginer 50% mode, shes having a blast drivng it, what is the absolute absolute lowest gearing i can install in this little merv? i changed it so far to a 19/50 i think, is there a lower pinion than a 19 for the titan 550? thanx in advance, luvin this little thing