S&S MR103C chain drive camshaft kit for 1999-'06 HD® Big Twins except '06 HD® Dyna® are recommended for modifed engines with larger displacement and higher compression. More torque and horsepower than bolt in cams can deliver. Stock valve springs in 2005-'06 engines may be used with MR103 and HP103 cams. An S&S oil pump and cam support plate, along with a stock 2007 and later style hydraulic cam chain tensioner upgrade is highly recommended for chain drive cams.
