Ford 4.6L 5.4L Modular V8, .800 Under Head Length, M10 x 1.0 Thread Size, Pro Series ARP Flexplate Bolt Kit 254-2901ARP Flexplate bolts play an important role in the performance and safety of race cars and street machines alike. Thats why the fastener experts at ARP have developed special bolts that are far superior to OEM hardware. ARP offers two styles of ARP Flexplate bolts bolts: High Performance and Pro Series.Both ARP Flexplate bolts are forged from aerospace alloy and heat-treated prior to thread rolling and machining. Both feature an exclusive, flat, 12-point head design and larger than stock shank diameter for increased strength nd improved Flexplate register.The popular ARP High Performance series is rated at 180,000 psi, and the premium grade ARP Pro Series, originally developed for NASCAR Winston Cup competition, has a 200,000 psi rating. Complete with washers and nuts where applicable.NOTE: The thread size of metric fasteners is listed using international designations. For example, M10 indicates a 10mm thread size.