ARP Main Stud Kit Evo 4-9

There are many important reasons to use ARP® main stud kits, including the elimination of main cap walk and fretting, as well as protecting the threads in your engine block. The studs are manufactured in our own factory using the best materials, processes, designs and engineering. Every ARP® main stud kit exceeds the most stringent aerospace specifications.

All kits come complete with hardened parallel-ground washers and aerospace quality nuts. Some applications have provisions for mounting windage trays and have specially designed standoff studs with serrated lock nuts to position the windage tray and lock it securely in place. The studs are manufactured from 8740 chrome moly steel, heat-treated in-house to 190,000 psi tensile strength, and precision J-form threads rolled after heat-treat to create a fastener that has threads 1000% stronger than others. Don’t settle for anything less than the best. Insist on genuine ARP® studs… you’ll find the name stamped right on the end!

These 4G63 ARP main studs are made from 8740 chromoly steel and have a 190,000 psi tensile-strength rating. They are precision centerless-ground and thread-rolled to Mil-S-8879 specs, with a black oxide finish for corrosion resistance. The kits come complete with hardened washers and high-strength hex nuts. They are perfect for helping to keep your main girdle in place and reduce bearing fatigue or distortion. After install have line bore checked or trued by a machine shop.