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
  • .984-inch Length
  • Fits GM LS Engines with 1/4-inch Wide Flange
  • PROFORM Parts Brand Product
  • Sold as Set of 12
  • More From This Category

    GO FAST BITS TMS Valve, Respons TMS (For Hyundai/ Kia)

    GO FAST BITS TMS Valve, Respons TMS (For Hyundai/ Kia)

    $357.30 $397.00

    10% OFF
    KB Piston, 4 in. Bore, For Chevrolet 350 Rod 5.700 Flat Top 0cc No Valve, .030 Oversized, w/ Rings, Each

    KB Piston, 4 in. Bore, For Chevrolet 350 Rod 5.700 Flat Top 0cc No Valve, .030 Oversized, w/ Rings, Each

    $1,025.42

    MANLEY Piston, 1.375 in. Compression Distance, 85 mm Bore Size, -8cc Dish, For Mitsubishi Eclipse GS/GST, Set of 4

    MANLEY Piston, 1.375 in. Compression Distance, 85 mm Bore Size, -8cc Dish, For Mitsubishi Eclipse GS/GST, Set of 4

    $1,429.40