Chev 454 BBC ARP Main Stud Kit # 135-5601Main Studs, 4 Bolt Main, Chevy, Big Block, Kit Main Bolt Style: 4 bolt Fastener Style: Stud Fastener Nut Style: Standard hex Works with Windage Tray: No Fastener Tensile Strength (psi): 190,000 psi Nuts Included: Yes Washers Included: Yes Quantity: Sold as a kit. ARP Main Stud Kits ARP main stud kits help eliminate main cap walk fretting and protect the threads in your engine block. They include studs made from 8740 chromoly steel and heat treated in