ARP DODGE 5.9L DIESEL MAIN STUD KIT. These ARP main studs are made from 8740 chromoly steel and have a 200,000 psi tensile-strength rating. They are precision centerless-ground and thread-rolled to Mil-S-8879 specs, with a black oxide finish for corrosion resistance. The kits come complete with hardened washers and high-strength hex nuts.