Proform Wedge-Locking Header Bolts - Black Oxide (PR66756)

PR66756 - WEDGE LOCKING HEADER BOLTS 16

Suit BB Chev 396-502, Ford 5.0L, SB Ford 289-302-351W, Mopar 413

Part Number: PR66756

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.
Features:
Grade 8 (12.9) Steel
Hex Head Type
1-inch Length
Fits GM BB 396-502 exc 348 and 409, Ford 5.0L, SB 289-302-351W, Mopar 413
Sold as One Set of 16 Pieces