ARP 247-4205 12v Cummins ARP625 (Super Alloy) Head Stud Kit

ARP 247-4205 Pro Series cylinder head studs are cold-forged to ensure molecular integrity. They are heat-treated prior to thread rolling and machining, and all kits come complete with hardened parallel washers for even load distribution and accurate torque readings.

It is for good reason that virtually every top professional engine builder relies on ARP Pro Series head studs for their all-out competition powerplants. Simply stated, there’s not a better stud setup on the market today. ARP uses a premium grade 8740 alloy that is rated far superior to aircraft quality. Then each stud is placed vertically in special racks and precisely heat-treated to 260,000 psi. ARP studs are thread rolled after the heat treatment, which gives them about 1000% (that’s ten times) better fatigue strength than those studs that are threaded before heat treatment (a very common industry practice).