Most S&S cams have higher lift than stock and are designed to take advantage of the extra flow of ported stock heads or S&S Super Stock heads. Due to the high lift of these cams, S&S adjustable pushrods are recommended. To get the best performance from a performance cam installation, a high flow intake and exhaust system is also recommended. Quick installation and Easy Start Cams allow stock starter to start any engine. Kit contains cams, gearcover gasket, cam bearings, and instructions. Great way to increase performance at an affordable price Quick installation - reuse many stock components Kit contains 635HO camsshafts, Installation Kit: gearcover gasket, bearings, retaining ring, o-ring, thread lock, Instructions 2005-up stock valve springs will handle camshafts with lift up to 0.585". If a camshaft with higher lift is installed, high performance valve springs capable of handling a greater lift must be used. Cams with over 0.585" of lift will cause interference between the valve spring top collar and the valve seal with stock cylinder heads HP103 Camshafts are designed as bolt in cams for engines with 103 and stock 9.7:1 compression up to 10.5:1. Works well with stock, un-ported heads, but is great for S&S Cycle CNC ported heads. Best power in the higher rpm range, 3000-6000 rpm. Bolt-in cam for stock 103 engines