It is for good reason that virtually every top professional engine builder relies on ARP Pro Series head studs for their all-out competition power plants. Simply stated, there’s not a better stud setup on the market today. For openers, ARP uses a premium grade 8740 alloy that is rated far superior to “aircraft” quality. Each stud is placed vertically in special racks and precisely heat-treated to 200,000 PSI. This procedure ensures complete heat penetration and the results are far superior to those lesser quality studs from other manufacturers who just dump pieces in a basket and hope for the best.