ARP Head Stud Kit, Cummins 4BT 3.9L, ARP2000

If your building a high horsepower engine you need to start with the strong foundation, ARP (Automotive Racing Products) is known for their quality fasteners. Top professional engine builders and enthusiasts know that ARP Pro Series head studs are the best you can get. Using 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, giving them 10 times the fatigue strength of other studs. Centerless grounded for near-perfect concentricity (something lesser quality studs don't even do), this allows for all parts to slide effortlessly into position and alignment.