For AMC 401 with Indy heads, ARP 114-3603 High Performance Cylinder Head Bolts feature a Hex Head.
High Performance head bolts are available with a reduced wrenching hex or 12-point and wide area flanged head, which eliminates the need for valve train removal to facilitate cylinder head retorquing.
All High Performance Series bolts are rated at 180,000 psi, which is 15% stronger than Grade 8, and kits come complete with hardened parallel-ground washers.
All Pro Series bolts are cold-forged to ensure molecular integrity, heat-treated prior to thread rolling and machining, and are nominally rated at 200,000 psi.
ARP Pro Series head bolt kits are application specific, designed for use with typically competition only components.
These fasteners deliver superior strength and meet the ARP “ZERO defect – ZERO failure” quality standard.
Each kit includes hardened and parallel-ground washers to ensure even load distribution and accurate torque readings.
All Pro Series head bolts have a reduced wrenching hex or 12-point head and wide area flange, eliminating the need for valve train removal for cylinder head retorquing and permitting the use of larger diameter valve springs.
Most applications have undercut short bolts that can help eliminate head gasket failures through providing more “stretch” to compensate for the additional compression of gaskets.
