ARP 235-4102 Pro Series Cylinder Head Studs Kit for Chevrolet Big Block with Brodix -2 -4 2X 3X Canfield HolleyFastener Style: Stud Undercut Stud: No Head Style: Hex Fastener Material: 8740 chromoly Fastener Finish: Black oxide Washers Included: Yes Cut to Fit: No Pro series cylinder head studs from ARP are cold forged to ensure molecular integrity. They are heat treated prior to thread rolling and machining and are rated at a whopping 220,000 psi. ARP Pro series kits are also available with 12 point nuts, and all kits come complete with hardened parallel