ARP Pro Series Bolts
All Pro Series bolts are cold-forged to maintain molecular integrity, heat-treated before thread rolling and machining, and meet the ARP ZERO defect - ZERO failure quality standard. ARP Pro Series head bolt kits are application-specific and designed to deliver the superior strength typically associated with competition engines.
Pro Series kits are available in two materials: standard 8740 with a 190,000 psi tensile strength rating, and proprietary ARP2000 with a 220,000 psi tensile strength rating where noted. All Pro Series head bolts feature a reduced wrenching hex or 12-point head design and a wide-area flange, allowing for the use of larger diameter valve springs and eliminating the need for valve train removal during cylinder head retorquing.
Each kit includes hardened parallel-ground washers. Many applications also feature undercut short bolts, which provide more stretch to compensate for additional gasket compression, helping to eliminate head gasket failures.