Proform Wedge-Locking Header Bolts; Hex Head; M8 X .984In; Chevy LS; Nickel Plt; 12 Pcs 66754

Each PROFORM 12.9 Steel (equiv. 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. It's 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.

Engine Header Bolts | Wedge-Locking Technology | Hex Head Type | M8 Thread X .984 Inch Long | Shiny Nickel Plated | 12.9 Steel | 12 Pcs in kit | Fits GM LS Engines with 1/4in Wide Flange