Prp Wedge-Locking Header Bolts – Black Oxide Finish, Pr66756

Description

Wedge-Locking Header Bolts – Black Oxide

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

PR66756

66756

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) SteelHex Head Type1-inch LengthFits GM BB 396-502 exc 348 and 409, Ford 5.0L, SB 289-302-351W, Mopar 413Sold as One Set of 16 Pieces

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