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

    Wilwood Caliper, AERO4-DS, Radial, 1.10 in. Rotor Width, 15.00 in. Rotor Dia, 1.12/1.12 in. Bore, Universal, Alum, Red, Each

    Wilwood Caliper, AERO4-DS, Radial, 1.10 in. Rotor Width, 15.00 in. Rotor Dia, 1.12/1.12 in. Bore, Universal, Alum, Red, Each

    $977.52

    Ross Performance External Oil Pump Wet Sump, Nissan RB30 (Australia), Gold, 12T, Kit

    Ross Performance External Oil Pump Wet Sump, Nissan RB30 (Australia), Gold, 12T, Kit

    $3,893.30

    Sonnax Lockup Relay Valve Sleeve Kit, A340, A340E, A340F, A340H, Each

    Sonnax Lockup Relay Valve Sleeve Kit, A340, A340E, A340F, A340H, Each

    $170.89

    TCI Electric Fan, Single, 16 in. Diameter, Reversible, 1,800 cfm, Black, Plastic, Each

    TCI Electric Fan, Single, 16 in. Diameter, Reversible, 1,800 cfm, Black, Plastic, Each

    $371.22

    Haltech ECU + Plug'n'Play Kits, Direct Plug-in ECUs, Elite PRO ECU - Ford Falcon i6 "Barra" + Onboard Wideband Sensor Kit Length: 2.5m (8'), Kit

    Haltech ECU + Plug'n'Play Kits, Direct Plug-in ECUs, Elite PRO ECU - Ford Falcon i6 "Barra" + Onboard Wideband Sensor Kit Length: 2.5m (8'), Kit

    $4,110.00