Edelbrock part #7821 Performer-Link timing chain is for use with Edelbrock or stock cams. They have a solid-bushing chain for a true bearing surface that rolls with the sprockets, eliminating chain stretch. Cam sprockets are made from 35,000 psi tensile strength cast iron. Crank sprockets are made from billet SAE-1144 steel and induction heat treated. Four Performer-Link sets are stock replacement parts and 50-state legal (see listings in bold type). All other sets have three keyway setting points to ensure accurate timing selection for early or late-model vehicles. Performer-Link timing sets are not for use above 6500 rpm. Performer roller chain sets are engineered to operate up to 6500 rpm. Never hammer directly on chain or sprockets. You can crack the hardened links and pins and cause early failures. Use a sleeve for installations that require hammering, a brass drift punch may be used if you carefully alternate blows on either side of the sprocket to avoid cocking. Never stretch the chain with a screwdriver. Check for clearance between the timing chain and block and between the chain and front cover before reassembly. Be sure that both cam and crank sprockets a re exactly in line with each other. Misalignment can cause chain to break.