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 tensioner's works well for all but the most demanding high performance applications The kit includes gear cover gasket and cam bearings