The Edelbrock Performer-Link True Rolling Timing Chain Set is used with either performance or stock cams. They have a solid-bushing chain for a true bearing surface that rolls with the sprockets, eliminating chain stretch. The crank gears are machined and made from billet SAE-1144 steel and induction heat-treated. The cam sprockets are made from 35, 000 PSI tensile strength cast iron. The Performer-Link timing sets are not for use above 6, 500 RPM. The thrust bearing, offset bushings, gaskets, bolts and studs are not included.