I have a question for the guys who know.

[What's_nitro?]

I wouldn't think so. Higher RPM makes the controller work harder, outputting more pulses to the motor. The fact that to go a certain speed the vehicle requires a certain amount of power, coupled with the higher RPM would be a step in the wrong direction. You would also run a higher risk of burning the motor. Though if the vehicle were lighter because of it, you might see a few more MPH from that power. I'm not sure if it would help so much with the torque, either, because although the smaller motor has less it would just be multiplied by the lower gearing.