Wedge-Locking Header Bolts
- Grade 8 (12.9) Steel
- Hex Head Type
- 3/4-inch Length
- Fits GM V6, SB 265-400, Buick, Olds, Pontiac '79 and earlier, Mopar BB 383-440 exc 413, AMC V8's w 3/8" bolts
- PROFORM Parts Brand Product
- Sold as One Set of 12 Pieces
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.
- Wedge-Locking Technology Eliminates Constantly Re-Tightening Exhaust Collector Bolts; Blocks Bolt-Loosening Rotation caused by Vehicle Vibrations.
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