S&S Cycle 0925-0540 330-0017509G Camshaft Kit - 509G Gear Drive - Twin Cam - 99-06Features Bolt in cams for 88 CID engines with stock compression ratios Increases valve timing accuracy by eliminating timing chain lash and loosely fit stock chain drive Reverses the rear cam's direction of rotation, providing additional operating clearance between cam lobes; resulting in higher cam lifts that are possible with the gear kit Material must be removed from inner surface of the stock gear cover to install S&S recommends that adjustable