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

    Classic Instruments Gauge Set, The Moal Bomber, Universal

    Classic Instruments Gauge Set, The Moal Bomber, Universal

    $1,417.94

    Connecting Rod Bearing Set

    Connecting Rod Bearing Set

    $88.48

    ARP Bolts, 8740 Chromoly, Black Oxide, 12-Point Head, 1/2-13 in. Thread, 1.25 in. UHL, Set of 5

    ARP Bolts, 8740 Chromoly, Black Oxide, 12-Point Head, 1/2-13 in. Thread, 1.25 in. UHL, Set of 5

    $36.84

    PowerBond Balancer OEM Replacement For Ford 460 BIG BLOCK F250 F350

    PowerBond Balancer OEM Replacement For Ford 460 BIG BLOCK F250 F350

    $183.17

    Trick Flow Pushrods, 5/16 in. Diameter, 7.950 in. Long, 4130 Chromoly, 0.080 in. Wall, For Guideplates, Set of 16

    Trick Flow Pushrods, 5/16 in. Diameter, 7.950 in. Long, 4130 Chromoly, 0.080 in. Wall, For Guideplates, Set of 16

    $305.95