ANDREWS - 50 SERIES CAMS FOR TWIN CAM Andrews Products grinds its cams using computer-aided cam design capabilities. This superior technology gives the utmost in both performance and reliability. Only the best alloy steel billets and heat-treating processes are used. The power in a Harley Twin Cam engine is completely released only when superior Andrews computer-designed high-performance cams are installed. Can be used with stock valve springs and tappets. For lighter bikes. Designed for 95"+ motors with 9.25:1 to 9.50:1 compression ratio and stock heads. Cams work best at higher rpm of 2500-6000. Made in the U.S.A. NOTE: 59G, 60G and 64G cams are for highly tuned engines and require the knowledge of an expert engine builder for proper setup and installation. NOTE: All Andrews gear-driven cams require four-gear set for installation (DS-199532 or DS-199538 for 99-06 applications; 0925-0166 or 0925-0152 for 07-14 Twin Cam and 06 Dyna applications). NOTE: Installer must check coil bind, valve-to-valve clearance and valve-to-piston clearance. NOTE: Chain Driven Cams: 00-06 model cams use a splined cam drive sprocket. These cams will fit in the 1999 Twin Cam motor, but the splined cam drive sprocket OEM #25716-99 or DS-199175 must be used.