ARP 4373001 Stainless Steel Bolt Kit For Rear End Cover On Select GM 10-Bolt Applications A practical and good looking way to upgrade your GM 10-bolt rear end cover Manufactured from eye-catching, sturdy, rust-proof stainless steel Rated at 170,000 PSI, which is considerably stronger than Grade 8 hardware .750 under head length, and thread size is 5/16-18 Washers included