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

    Dakota Digital Gauge, MDX System, 1970-72 Chevy Malibu/ El Camino, Carbon Fiber Style Face, Red Display, Custom

    Dakota Digital Gauge, MDX System, 1970-72 Chevy Malibu/ El Camino, Carbon Fiber Style Face, Red Display, Custom

    $1,968.40

    DBA Front Street Series EV Brake Pads, For Tesla 3 Standard / Long Range (No Upgrade) 2019 On, Kit

    DBA Front Street Series EV Brake Pads, For Tesla 3 Standard / Long Range (No Upgrade) 2019 On, Kit

    $100.50

    KB Piston, 4 in. Bore, For Chevrolet 383, Rod 5.700, Flat Top +7cc 2V, .060 Oversized, w/ Rings, Each

    KB Piston, 4 in. Bore, For Chevrolet 383, Rod 5.700, Flat Top +7cc 2V, .060 Oversized, w/ Rings, Each

    $1,082.74

    Motive Gear Mainshaft Tr4050 17 in. Oa, Each

    Motive Gear Mainshaft Tr4050 17 in. Oa, Each

    $304.70

    DBA Front 4000 Series T3 Brake Rotor, 324mm, For Nissan Skyline R32/33/34 Twin Turbo 93, Kit

    DBA Front 4000 Series T3 Brake Rotor, 324mm, For Nissan Skyline R32/33/34 Twin Turbo 93, Kit

    $361.20