This Performance Kit has the same durability and reliability as the MTNTK Performance Fix Kit with more kick. The pistons are 100 grams lighter than the stock pistons so this kit produces a 5HP gain over stock with increased throttle response. If you want the dependability and proven track record MTNTK Performance has with a little more power, then this kit is for you. The all new MTNTK Performance Cheater Head is a must have for any snowmobile enthusiast looking to gain more horsepower and better throttle response without any fueling changes or additional engine modifications. Each head is machined to proper specs which results in perfect fitment. Domes Available in 13-1 or 15-1 Compression ratios and available for all '08-20 800 CFI Engines. Price includes the refundable core charge and when you order you will receive a machined head. You can return your head (even if it has damage) for a $75.00 credit. Order today! Some applications may require heavier clutch weights.