NEW! – Just released These head stud kits feature premium grade ARP 2000 material ( Not 8740 material as all previous kits ) that is rated at 220000 psi tensile strength. They are heat-treated prior to thread rolling and machining and are rated at a whopping 220000 psi. The pro series kits are also available with 12-point nut, and all kits come complete with hardened parallel washers for an even load distribution and accurate torque readings. 8740 material has a 190,000 psi
