Camshaft gear drive kits increase valve timing accuracy by eliminating timing chain lash and loosely-fit stock chain drive Reverses the rear cam’s direction of rotation, providing additional operating clearance between cam lobes; as a result, higher cam lifts are possible with the gear drive kit Kits include cams, inner gears, outer drive gears, inner and outer bearings, gasket and instructions Material must be removed from the inner surface of the stock gear cover to install S&S gear drive cams A hydraulic press and other professional-level tools are required to install these kits Cam bearings and gaskets must be replaced when installing new cams Kits require high-performance valve springs when installed in 99-04 models. Installer must check coil bind, valve-to-valve clearance and valve-to-piston clearance. Due to the inherent characteristics of gear drives, you may experience more valve train noise. Installer must check coil bind, valve-to-valve clearance and valve-to-piston clearance. Bolt-in cam for 103? and 106? Big Bore Twin Cam motors Use with stock heads (up to 10.2 compression) and low restriction intake and exhaust Great for lighter bikes with strong power from 3500-6000 rpm Made in the U.S.A.