I have a 1-speed on mine, and I have no issues with cramping. I used the stock magnum airbox (I know) and mag hi-torque head (I think). The only thing that was strange is the exhaust port is different so it hangs lower coming from the header. You can just fabricate a clamp for the rear. If I have a moment, I'll take a pic and post it later. No other problems though. You lose a noticable amount in initial acceleration, but I don't mind. Make sure you get the 2hp 1-speed engine to help, and the hi-torque head will assist too for power.