Gain huge throttle response and 4 hp with our new billet head kit for the 600 EV motor. A must for mountain maniacs who will increase there sleds power by 6-7 hp!!! Fits all 600 exhaust valve motors and works with premium pump gas. This kit installs easily under the stock head cover and has removeable domes so you can change compression ratios. You will notice an instant improvement in how fast the motor revs and responds. Fusion/IQ sleds will pick up rpm, mountain riders may have to add 1-2 grams of clutch weight. Please indicate high or low elevation domes when ordering. Works great with our Pipe Mod and V force reeds for a 10-13 hp gain on a Fusion/IQ!!!!