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

    Proform , Universal Piston Ring Installation Tool , Fits 2.50" To 5.00" Bore Sizes

    Proform , Universal Piston Ring Installation Tool , Fits 2.50" To 5.00" Bore Sizes

    $56.89

    Proform , Professional Crankshaft Turning Socket , Fits Chrysler V8

    Proform , Professional Crankshaft Turning Socket , Fits Chrysler V8

    $67.70

    Proform , 3" Diameter Exhaust Collector Gasket Kit, 3 Hole Type; Made from Soft Conforming Aluminum

    Proform , 3" Diameter Exhaust Collector Gasket Kit, 3 Hole Type; Made from Soft Conforming Aluminum

    $34.57

    Proform , Adjustable Thread-In Electric Fan Controller, Adjustable Between 150 to 240 Degrees F

    Proform , Adjustable Thread-In Electric Fan Controller, Adjustable Between 150 to 240 Degrees F

    $119.94

    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 , Buick Timing Chain Cover Die-Cast; w/ Oil Seal, Die-Cast; Optimizes OEM Design; w/ Crankshaft Oil Seal

    Proform , Buick Timing Chain Cover Die-Cast; w/ Oil Seal, Die-Cast; Optimizes OEM Design; w/ Crankshaft Oil Seal

    $625.24