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

    Cometic Head Gasket, MLS, Ford 4.0l, BA-on Barra 96mm, Compressed Thickness, Each

    Cometic Head Gasket, MLS, Ford 4.0l, BA-on Barra 96mm, Compressed Thickness, Each

    $308.65

    COMP Cams Engine Valve Spring Seat, ID Spring Locator, 1.300 in. OD, .520 in. ID, .060 in. Thick, Each

    COMP Cams Engine Valve Spring Seat, ID Spring Locator, 1.300 in. OD, .520 in. ID, .060 in. Thick, Each

    $9.94

    COMP Cams Pushrod, Magnum, Chromoly, Heat-Treated 7.300 in. Long, .080 in. Wall, 3/8 in. Diameter, Each

    COMP Cams Pushrod, Magnum, Chromoly, Heat-Treated 7.300 in. Long, .080 in. Wall, 3/8 in. Diameter, Each

    $21.28

    SAAS Catch Tank Banjo Hose Fitting 12mm 1/2

    SAAS Catch Tank Banjo Hose Fitting 12mm 1/2

    $15.04

    Sonnax Tool Kit, Chrysler, Ford A4Ld, AOD, AODe, Chrys 518, Each

    Sonnax Tool Kit, Chrysler, Ford A4Ld, AOD, AODe, Chrys 518, Each

    $879.22