S&S Power Pack For Harley Twin Cam Features: Largest big bore kit available without doing crankcase mods Upgrade Twin Cam 96 and Twin Cam 103 to 110 cu inches 10.5:1 Compression S&S 585 Easy Start Cams S&S premium tappets Quickee adjustable pushrods Cylinders fit to pistons No machining required All parts required to upgrade to gear drive cam or hydraulic cam chain tensioners Engineered package to deliver the best bolt-in performance available Pinion shaft runout must be less that .003 to use gear drive cams Not for use with S&S 79cc Cylinder Heads