Are you looking for track, or drags ?
For Track iv always been told, Mech Rear with Visc Front (still lets you turn)
For Drags Mech rear with Mech front with locked center (all 4 wheels MUST spin) no good for going around corners but :lol:
So ill be chasing a Mech/Visc combo (Maybe a EVOIII box is cheaper ?)