Features a 7/16” coarse thread into the case and 10mm dia through the head, to eliminate any machine work to fit the stud through the head. Case must be drilled and tapped to accommodate studs as well as enlarging stud holes through the cylinder head. Made from ARP's premium CVustomAge 625+ material and rated to 280,000 psi, ARP cylinder head studs not only offer superior clamp loads over cylinder head bolts, they provide proper alignment of the head and gasket with more accurate and consistent torque loading. Bolts will actually twist while torquing to proper spec, greatly reducing their ability to hold true.