For Chevy BBC 454 Chromoly Cylinder Head Bolt Kit Fits PCE Heads 8 Long Bolts USFor Chevy BBC 454 Chromoly Cylinder Head Bolt Kit Fits PCE Heads 8 Long Bolts US Big Block Chevy 454 12 Point Head Black Oxide Finish Our cylinder head fasteners are made from aircraft 8740 tensile strength Chromoly steel and cold forged to ensure molecular integrity. They are heat treated prior to thread rolling and machining and are rated at a whopping 190,000 psi. All kits come complete with 12 point nuts and hardened parallel washers for even load