Upgrade your engine build with the ARP Header Bolt Kit, specially designed for Chevy LS Gen III/IV engines. This kit includes 12 bolts featuring a 3/8" wide flange and 1.181" UHL, made from durable 8740 material. The 12-point socket size (10mm) ensures a secure fit. Enhance your performance with precise installation using M8 thread size, complete with washers.