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

    COMP Cams Cam / Lifters / Valvetrain Thumpr Hydraulic Flat Advertised Duration 279 / 297 Lift .4

    COMP Cams Cam / Lifters / Valvetrain Thumpr Hydraulic Flat Advertised Duration 279 / 297 Lift .4

    $1,267.70

    CVF Racing Water Pump Pulley, 2 Groove, LWP, Stealth Black Big Block For Chevrolet, Kit

    CVF Racing Water Pump Pulley, 2 Groove, LWP, Stealth Black Big Block For Chevrolet, Kit

    $175.12

    Haltech ECU + Universal Wiring Kits, Elite 750, Elite 750 + Basic Universal Wire-in Harness Kit Length: 2.5m (8'), Kit

    Haltech ECU + Universal Wiring Kits, Elite 750, Elite 750 + Basic Universal Wire-in Harness Kit Length: 2.5m (8'), Kit

    $2,009.00

    MANLEY Valve Lock, 10 Degree Machined, Bead Loc, PVC Titanium, .3110 in. Stem, Set of 8

    MANLEY Valve Lock, 10 Degree Machined, Bead Loc, PVC Titanium, .3110 in. Stem, Set of 8

    $314.35

    ARP Main Studs, 2-Bolt Main, Works with Windage Tray, For Chevrolet, Big Block, Kit

    ARP Main Studs, 2-Bolt Main, Works with Windage Tray, For Chevrolet, Big Block, Kit

    $213.39