In terms of motor mount the vast majority are a replacement for the centre diff mount on one side - basically extends out to allow the motor to mount. This is how the RC Monster and various conversions are done as well as the Caster. The only diference in layout tends to be that some have the motor to the rear of the chassis and some to the front to give more room for the cells.
The Novak and Tekno systems use a motor holder that clamps the moptor and attatches to the chassis in the same manner that a nitro mill would do.
