Sure-Lock Rocker Arm Nuts, .540" Shank OD, 3/8" Stud Size, Gold Tone Finish Suit Small Block Chevy & Ford 289-351W

For aluminium rocker arms only. Designed to keep the rocker arms positively locked for precise and critical valve train adjustments. Manufactured from quality grade steel, then heat-treated for extra strength and plated with a durable finish. Kits include 16 rocker arm nuts with socket head set screws and one hex key wrench.