The S&S 510C camshaft set is designed to be used with the stock H-D chain drive system and is an economical way to improve the performance of stock and slightly modified street engines. The S&S 510C cams are as quiet as stock but produce significant power increases across the rpm range, especially above 3000 rpm. The 510C cams are compatible with the stock splined chain sprocket used in 2000-up Twin Cam engines, but may be used in 1999 engines if the H-D 2000-up style splined rear cam sprocket is used. S&S’s 1999 FXD test bike produced 62 horsepower in stock con-figuration. Horsepower jumped to over 82 with 88 ft-lb. of torque after the installation of S&S .510" camshafts, adjustable pushrods, an S&S Super E carburetor and air cleaner, 6200 RPM Screamin’ Eagle ignition module, and S&S slip-on mufflers.