Material: -5Finish: BlackFord Big Block 390-428 cid FE Series, High Performance, ARP Main Bolts 155-5201ARP main bolts are far superior to any other main bolt kit offered for use in competition engines, ARP main bolts are designed to meet the exacting standards and demands of professional engine builders. ARP main bolts are Forged from 8740 chrome moly, all bolts feature generous under-head radius and rolled threads for the utmost reliability. The threads are rolled after heat treating, which gives them about 1000% longer fatigue life than most main bolts, which are threaded prior to heat-treating. ARP main bolts are available in the popular High Performance Series, which, at a nominal rating of 180,000 psi, is a premium replacement for OEM fasteners, or the 200,000 psi nominal rated Pro Series, application-specific main bolts with reduced wrenching head and are designed for use in competition applications. ARP provides Parallel-ground, hardened washers that are included with each kit.
