To overcome head gasket failure in truck and RV diesel engines, ARP offers extra heavy-duty head studs for GM, Dodge, and Ford applications.Studs made of proprietary ARP 2000 material in Santa Paula, CARated at 220,000 psi tensile strengthAmple clamping force prevents cylinder heads from liftingThreads rolled after heat treatment for optimum fatigue strengthCenterless ground to assure perfect concentricityBroached stud ends install & make cylinder head removal easierChrome moly steel 12-pt nuts & parallel-ground washers included