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
  • .984-inch Length
  • Fits GM LS Engines with 1/4-inch Wide Flange
  • PROFORM Parts Brand Product
  • Sold as Set of 12
  • More From This Category

    Proform , Carburetor Main Body for 650 CFM Carburetor, Adjustable Air Bleeds & Down-Leg Boosters

    Proform , Carburetor Main Body for 650 CFM Carburetor, Adjustable Air Bleeds & Down-Leg Boosters

    $366.12

    Proform , Chevy Small Block Header Gasket Kit, Conforms to Surface of Exhaust Header

    Proform , Chevy Small Block Header Gasket Kit, Conforms to Surface of Exhaust Header

    $48.96

    Proform , Tundra Series Oil & Transmission Cooler, Universal Stacked Plate Design - 25 Row Model

    Proform , Tundra Series Oil & Transmission Cooler, Universal Stacked Plate Design - 25 Row Model

    $360.14

    Proform , Electric Water Pump Big Block Chevy; Blue, Blue Finish, Black Motor Cap; Die-Cast Aluminum

    Proform , Electric Water Pump Big Block Chevy; Blue, Blue Finish, Black Motor Cap; Die-Cast Aluminum

    $504.47

    Proform , Tundra Series Oil & Transmission Cooler, Universal Stacked Plate Design - 16 Row Model

    Proform , Tundra Series Oil & Transmission Cooler, Universal Stacked Plate Design - 16 Row Model

    $264.21