S&S CYCLE 0925-0959 106-4868 551G Gear Drive Camshaft Kit - 551G Gear Drive - Twin Cam | DynaFeatures Designed for engines with 96 to 106 CID and 9: 1 to 9: 9 compression, this is a bolt in cam set for stock or mildly modified touring bikes Reverses the rear cam's direction of rotation, providing additional operating clearance between cam lobes making higher cam lifts possible More power across the rpm range, with improved low and midrange torque, strongest from 1,000 4,000 rpm Increases valve timing accuracy by eliminating timing chain lash