Melling timing chain sets are designed for use 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 from stress-proof steel. Most Melling timing chain sets have three keyways to ensure accurate timing for early or late model vehicles, and to allow you to set the cam timing at 4 degrees advanced, 4 degrees retarded, or stock. However, 50-state (stock replacement) sets have single keyways. The chains are available in several styles, such as single or double roller, single non-roller, and link belt. Melling timing chain sets are not for use above 6,500 rpm. Order the model designed for your vehicle application.