This high strength, heat treated alloy steel cam drive kit is designed to increase the gear to shaft strength. The OE style spacer has been eliminated and the involute spline width of the gear has been increased by approximately 1/4 inch. Includes a Grade 8 mounting bolt with a hardened steel washer. Three spacer shims are to duplicate the OEM length. This kit is a must for any cam change. Also fits any splined style Screaming Eagle or aftermarket cam for Twin Cam 1999.