F20C's are S2000 motors and will not work without major modification because A. they are a rear wheel drive setup and B the engine is reversed(meaning it spins the opposite of a H22 or F20B). I called HMotors and the only difference between the 2 is that the F20B has a shorter storke and less torque. Only Factor of the F20B is that its different. Stick with the H if you dont have alot of money