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

    Autometer Gauge Mount, Dash Top, Triple, 2 1/16", Subaru Impreza/Wrx/Sti 02-07, Mounting Solutions

    Autometer Gauge Mount, Dash Top, Triple, 2 1/16", Subaru Impreza/Wrx/Sti 02-07, Mounting Solutions

    $107.97

    PWR For Ford F100 1953 55MM Radiator

    PWR For Ford F100 1953 55MM Radiator

    $1,742.55

    QA1 H Series 3 Piece Alloy Rod End, 5/16in. Bore, 5/16in.-24 LH Male Thread, PTFE Lined

    QA1 H Series 3 Piece Alloy Rod End, 5/16in. Bore, 5/16in.-24 LH Male Thread, PTFE Lined

    $30.55

    QA1 NPB Series Spherical Bearing, Stainless Steel, 5/8in. Bore, PTFE Lined

    QA1 NPB Series Spherical Bearing, Stainless Steel, 5/8in. Bore, PTFE Lined

    $48.58