With performance enthusiasts adding increasing amounts of turbo boost to diesel applications, ARP has provided an extra measure of security in the form of extra-strong head studs manufactured from the firm's proprietary Custom Age 625+ material that has a minimum rating of 260,000 psi tensile strength. They are engineered to provide the clamping force required to keep cylinder heads from lifting due to exceptionally high combustion pressures.

The studs are manufactured in ARP’s Santa Paula, CA plant, with threads rolled after heat-treat to provide optimum fatigue strength. They are centerless ground to assure perfect concentricity. The ends of the studs are broached to facilitate easy installation. This feature also enables the cylinder head to be removed in tight quarters.