Each PROFORM Grade 8 Header Bolt is permanently assembled with a pair of special washers. When the bolt is torqued to 28+ ft-lbs, the washers super-hardened external teeth bite into and grip the bottom of the bolt head and the top surface of the header. After being self-locked in this manner, any bolt-loosening rotation is blocked by a wedge-locking action created by the washers interfacing, matching cams. Its an uphill climb: vibration that might ordinarily loosen the bolt actually increases the wedge-locking tension, securing the bolt even more. Because this simple wedge-locking method uses tension instead of friction, contact with oil actually facilitates the wedge effect. When changing headers, PROFORM Header Bolts can be untightened with a normal wrench, lubricated, and reused.

Features:
Grade 8 (12.9) Steel
  • Hex Head Type
  • 1.181-inch Length
  • Fits GM LS Engines with 3/8-inch Wide Flange
  • PROFORM Parts Brand Product
  • Sold as Set of 12
  • More From This Category

    LUCAS Power Steering Fluid, 1 Quart (950 ml), Each

    LUCAS Power Steering Fluid, 1 Quart (950 ml), Each

    $12.01

    MANLEY Valve, Race Master, Exhaust, 28.5 mm Head Dia, 6 mm Stem Dia, 98.05 mm Length, For Toyota Supra, Set of 12

    MANLEY Valve, Race Master, Exhaust, 28.5 mm Head Dia, 6 mm Stem Dia, 98.05 mm Length, For Toyota Supra, Set of 12

    $599.01

    Autometer Gauge Mount, Direct Fit, (3 3/8" X2, 2 1/16" X4), Ford Ranger 67-72, Mounting Solutions

    Autometer Gauge Mount, Direct Fit, (3 3/8" X2, 2 1/16" X4), Ford Ranger 67-72, Mounting Solutions

    $374.79