Engineered and manufactured for reliability these alloy steel flywheel bolts are heat treated to Grade 8 specifications for extra strength. Kits are complete with lock washers where needed and are black plated to help resist rust and corrosion.Features. Compatibility - AMC Pontiac. Head Type - Hex. Thread Size - 12 in.-20. Underhead Length - 1 in.. Material - Steel. Finish - Black Oxide. Color - Black