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 , Locking GM Turbo 400 Transmission Dipstick, Black finish; Computer modeled for precise fit

    Proform , Locking GM Turbo 400 Transmission Dipstick, Black finish; Computer modeled for precise fit

    $65.09

    Proform , Stamped Steel Air Cleaner w/ Tri-Star Wing Nut, Chrome; Deluxe Model; No Logos; 14" Diameter

    Proform , Stamped Steel Air Cleaner w/ Tri-Star Wing Nut, Chrome; Deluxe Model; No Logos; 14" Diameter

    $85.10

    Proform , Chevrolet Big-Block Slant-Edge Valve Covers, Liquid Black; Tall; Raised and Milled Emblems

    Proform , Chevrolet Big-Block Slant-Edge Valve Covers, Liquid Black; Tall; Raised and Milled Emblems

    $781.26

    Proform , Digital Mini RPM Shift Light, Black; 100 to 12,000 RPM Ranges; 1-12 cylinder range

    Proform , Digital Mini RPM Shift Light, Black; 100 to 12,000 RPM Ranges; 1-12 cylinder range

    $109.37

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

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

    $52.42