S&S Cycle 2006 Dyna 570C Chain Drive Camshaft KitThe 570 cam is designed for 88 to 96 inch engines with compression ratios between 9: 1 and 10: 1. Many riders are leery of the stock chain cam drive in late model big twins. While it is true that the early version introduced in 1999 was 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. The new chain