Cylinder fits to piston; no machining required. TC3 cam support plate and TC3 oil pump to ensure consistent oil pressure and engine longevity. Includes an S&S 4″ big-bore cylinder kit with 10.5:1 pistons, S&S 585 Easy Start cams, S&S Quickee Pushrods, and Premium Hydraulic tappets to make the most of the added displacement. Made in the U.S.A.. Not for use with S&S 79cc heads.. Can be used with stock heads..