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

    DBA Street Series Wheel Cylinder, For Daihatsu, Kit

    DBA Street Series Wheel Cylinder, For Daihatsu, Kit

    $60.30

    Sonnax Rear Sun Gear, Allison, Mt 600 Series, Each

    Sonnax Rear Sun Gear, Allison, Mt 600 Series, Each

    $214.14

    Oil Pump

    Oil Pump

    $127.72

    Whiteline Mount Bushing, 46.5mm OD, 23mm ID, Mazda, Kit

    Whiteline Mount Bushing, 46.5mm OD, 23mm ID, Mazda, Kit

    $26.48

    CVF Racing Alternator Bracket, Fuelie or Camel Hump Heads, LWP, For Chevrolet Small Block, Kit

    CVF Racing Alternator Bracket, Fuelie or Camel Hump Heads, LWP, For Chevrolet Small Block, Kit

    $177.28

    DBA Front Street Series XGold Brake Rotor, 338mm, For BMW 135i E82 & E88 Twin Turbo 3.0L 2008-2010, Kit

    DBA Front Street Series XGold Brake Rotor, 338mm, For BMW 135i E82 & E88 Twin Turbo 3.0L 2008-2010, Kit

    $297.60