ARP MAIN BOLT KIT - ARP-134-5001

Far 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 8470 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 bolts that are threaded prior to heat-treating. The popular High Performance Series is rated at 180,000 psi, and is a premium replacement for OEM fasteners. Hardened parallel-ground washers are included with each kit.

STUDS vs. BOLTS

ARP recommends the use of main studs over bolts whenever possible for several key reasons. First is the ability to obtain more accurate torque readings because studs don’t “twist” into the block. All clamping forces are on one axis. By the same token, there is less force exerted on the block threads, which contributes to improved block life (very critical on aluminum blocks). Finally, there are factors of easier engine assembly and proper alignment of caps every time.