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

    MANLEY Valve, Extreme/Severe Duty, Exhaust, 1.94 in. Head Dia, 0.3715 in. Stem Dia, 5.65 in. Length, Gen II, Each

    MANLEY Valve, Extreme/Severe Duty, Exhaust, 1.94 in. Head Dia, 0.3715 in. Stem Dia, 5.65 in. Length, Gen II, Each

    $85.44

    Wilwood Caliper, CPB, Radial, 0.81 in. Rotor Width, 13.00 in. Rotor Dia, 1.34 in. Bore, RH, Alum/Steel, Red, Each

    Wilwood Caliper, CPB, Radial, 0.81 in. Rotor Width, 13.00 in. Rotor Dia, 1.34 in. Bore, RH, Alum/Steel, Red, Each

    $411.57

    DBA Front Street Series Brake Hose, For Honda Front L/H, Kit

    DBA Front Street Series Brake Hose, For Honda Front L/H, Kit

    $42.80

    Motive Gear C-Mt-Sm465 (045) Fbr:Ld,1-1/16, Each

    Motive Gear C-Mt-Sm465 (045) Fbr:Ld,1-1/16, Each

    $39.10