.510" 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. Great cam for motors with 95 inches and 9.8 to 10.2 CR. Lower TDC lift for easy installation. Similar to TW37 with timing setup for higher compression. Stock springs OK. (2400–5600 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.