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

    ARP Cylinder Head Bolts, 12-point Head, High Performance, For Chevrolet BB, Mark V or Mark VI Block, late Bowtie, AFR & Heads, Kit

    ARP Cylinder Head Bolts, 12-point Head, High Performance, For Chevrolet BB, Mark V or Mark VI Block, late Bowtie, AFR & Heads, Kit

    $254.60

    Dakota Digital Gauge Kit, Direct Fit, 1968 For Camaro with Console gauges, Analog/Digital, Black Background, Multicolor Illuminated Display, Kit

    Dakota Digital Gauge Kit, Direct Fit, 1968 For Camaro with Console gauges, Analog/Digital, Black Background, Multicolor Illuminated Display, Kit

    $3,713.36

    Dakota Digital Gauge, MDX System, 1953-55 Ford F100, Black Alloy Style Face, White Display, Custom

    Dakota Digital Gauge, MDX System, 1953-55 Ford F100, Black Alloy Style Face, White Display, Custom

    $1,968.40

    Wilwood Bolt, Various, Alloy Steel, Kit

    Wilwood Bolt, Various, Alloy Steel, Kit

    $41.51

    MANLEY Rotating Assembly, 4.375 in. Stroke, 4.600 in. Bore Size, 6.535 in. Rod Length, +43cc Dome, BBC 582, Kit

    MANLEY Rotating Assembly, 4.375 in. Stroke, 4.600 in. Bore Size, 6.535 in. Rod Length, +43cc Dome, BBC 582, Kit

    $7,205.91