What a difference!! Our new billet head added a full 5-6 hp on our test sled with unbelievable acceleration and throttle response. The best part is that compression stays virtually the same as stock for excellent reliability. This head has twice the cooling capacity of stock due to our unique cover and dome design to keep those big motors cool. Trick look and removable domes make this the head to have on your Cat 1000 twin. Comes with head cover, set of domes, o-rings, and instructions. Fits 2007-2011 model years. Only low elevation domes are available.