High performance cylinder head kit that works well with stock up to 110" capacity. 89cc combustion chamber provides a slightly higher than stock; but still manageable compression ratio in larger than stock engines. A good choice for touring bikes and other heavy bikes. The installed S&S High performance valve springs allow the installation of camshafts with up to .650" lift. Compatible with stock bolt pattern crancases; rocker boxes; exhaust; and intake manifolds. Machined for S&S electric or manual compression releases (sold separately; if required). The large 2.000" intake and 1.605" exhaust valves maintain port velocity for good low and midrange response; but supply enough air for slightly larger engines to perform to their full potential. Intake ports flow 264 cfm (Cubic Feet per Minute) of air compared to stock heads at 182cfm. The wrinkle black powder coat finish to match stock black engine components.