I KNOW THAT A B01A IS A OFFROAD MOTOR I JUST GOT A MRX4-R AND RITE NOW THAT IS THE ONLY MOTOR I HAVE. I WAS THINKING I COULD PUT A TALLER GEAR OR RUN A TYPE OF PIPE THAT WOULD GIVE ME MORE TOP END,THE TRACK THAT I RUN AT IS TIGHT ENOUGH THAT A LITTLE MORE TOP END WOULD BE ENOUGH.....THANX....MIKE

Yes, you can fit an offroad engine in an onroad but you will not get the speed.

Because the better torque you can try 18/21 pinions on the clutch.