Bolt on big bore kits mean easy installation with no machining and no rebalancing S&S bolt-in cams and premium tappets make the most of the added displacement Cams are .482" lift and 240? duration intake and 234? duration exhaust Compression ratios: 9.6:1 for 1200cc kit and 11.2:1 for 1250cc kit Easy installation; bolt-on parts, no machining, no rebalancing Use stock heads, pushrods, and fuel system. KIT HOOLGN 883-1200 SLVR