Due to head lift issues at high WHP, additional clamping force is needed. While standard ARP studs can be torqued down to 65-70ft/lbs, these ARP made with 262,000psi tensile strength L19 steel can be torqued down to 90-95 ft/lbs easily, without breaking the stud. These are a direct drop in replacement, and require no special block modifications or machining. We feel so strongly about these extreme duty L19 studs, that we will no longer carry the standard ARP head stud, as they have proven unreliable beyond 525whp, due to insufficient clamping force.

Please note: ARP states that it's very important not to touch L19 studs with your bare hands; always use gloves when handling.