ARP Main Bolt Kit - Subaru BRZ 2.0L FA20 - 260-5001Far superior to any other main bolts available for use in competition engines, ARP main bolts are designed to meet the exacting standards and demands of professional engine builders. Forged from 8740 chrome moly steel, all ARP main bolts feature a reduced wrenching head, large underhead radius and rolled threads for the utmost in reliability. The threads are rolled after heat treating which gives them about 2000% better fatigue strength than most main