.550" valve lift. Set includes two chain driven camshafts. A cam drive installation kit; that includes a gear cover gasket; cam bearings and retaining ring can be ordered separately as S&S 503593. Cams can be run with stock hydraulic lifters. 88-103 inch engines. 9.8 to 10.2 CR. Maximum torque and horsepower at higher RPM ranges. Use high-lift springs. 2600-6200 RPM. Note: Owners of 1999 Twin Cams must separately purchase the splined 00-06 style driven gear (503575 Andrews). 00-06 models can re-use stock 34 tooth driven gear. Note: When using 99-06 chain drive cams for higher lift applications it is recommended to upgrade to gear drive or to convert to the 06-up hydraulic chain tensioners.