Proform Header Bolts, Black
Engine Header Bolts; Wedge-Locking Technology; Hex Head Type; 3/8-16 Thread X 3/4 Inch Long; Black Oxide Finish; 16 Pcs in kit; Fits GM BB 396-502 exc 348 and 409, Ford 5.0L, SB 289-302-351W, Mopar 413
- 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.