This stud uses heat treated grade 8 alloy steel. The enlarged radius base provides extra strength for a more durable stable shank. Black plated finish. Fits Chevy small block and Ford small block. Ultra Seal Competition Screw-In Rocker Arm Stud Set; 3/8 in.-24 x 1.75 in. Top; 7/16 in.-14 Bottom; 16 pc.;.