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

    ARP Cylinder Head Stud, Pro-Series, Hex Head U/C Studs, For Ford SB, 289-302, 5.0L w/ 351 Windsor Head, Kit

    ARP Cylinder Head Stud, Pro-Series, Hex Head U/C Studs, For Ford SB, 289-302, 5.0L w/ 351 Windsor Head, Kit

    $366.86

    ARP Wheel Stud Kit, Honda Civic Type R 2017-On

    ARP Wheel Stud Kit, Honda Civic Type R 2017-On

    $120.34

    Autotechnica Car Cover - Premium Hail Cover Evolution Medium Hail Cover Fits Cars Up To 444cm

    Autotechnica Car Cover - Premium Hail Cover Evolution Medium Hail Cover Fits Cars Up To 444cm

    $282.15

    Crow Cams Pushrod, 7.100 Length, 3/18in. Diameter, .138 Thick, 210 Radius, Each

    Crow Cams Pushrod, 7.100 Length, 3/18in. Diameter, .138 Thick, 210 Radius, Each

    $26.59

    DBA Front Street Series Brake Pads, For Landrover DIscovery ES HSE & Range Rover 95-06, Kit

    DBA Front Street Series Brake Pads, For Landrover DIscovery ES HSE & Range Rover 95-06, Kit

    $80.40