The ARP Pro Series Main Bolt Kits are forged from premium 8740 chrome moly and all the bolts feature generous under-head radius and heat treating for utmost reliability. The threads are rolled after heat treating, which makes them about 1000% stronger than most other main bolts. These bolts are nominally rated at 200,000 psi, and are application-specific main bolts with reduced wrenching head and are designed for use in competition applications. Parallel-ground, hardened washers are included with each kit.
ARP has developed a number of special fasteners for Porsche 911 and 930 Turbo and Non Turbo applications that provide the reliability needed for serious competition. These fasteners are manufactured from high grade materials, and are superior to OEM Porsche bolts and studs.