The Aeroflow harmonic balancer bolt is designed to suit Ford Windsor small block 289 to 351 and big block 460. Manufactured from aircraft quality 8740 high tensile strength chromoly steel and cold-forged to ensure molecular integrity within the stud. Meaning these are rated up to 190,000 psi making them stronger than Grade 8 and OEM fasteners. They feature a high hex head to prevent socket slippage while rotating the engine during assembly or routine service inspections. An extra thick ground washer is provided to allow for a more accurate, uniform torque.