S&S Cycle SS106-4383 625C Chain Drive Camshaft Kit for Twin Cam 07-17/Dyna 2006Description for S&S Cycle 625C Chain Drive Cam Kit While it is true that the early version introduced in 1999 was often not well suited to high performance applications, the later version introduced in the 2006 Harley Davidson Dyna model, and later incorporated in all Big Twins in the 2007 model year, was vastly improved Experience has shown that the new chain drive with hydraulic chain tensioners works well for all but the most demanding high