Speedmaster Easy-just Timing Chain Set allows you advance or retard your timing 6" without having to remove your valve covers or having to back off your rocker arms. Exact Radial run out tolerance insures your timing adjustments are accurate. Features a billet cam and crank sprocket. The crank sprocket is also heat treated for additional strength. Heavy-Duty roller chain and one-piece roller thrust bearing assembly insure smooth operation. Features: Adjustable: +6" (advance) or -6" (retard) Aircraft Quality adjusting bolts Premium billet steel cam and crank sprockets Heat-treated crank sprocket One-piece roller thrust bearing assembly Super heavy duty racing double roller chain