Wedge-Locking Header Bolts Hex Head 3/8 Diameter X 3/4 Inch Blk Oxide 16 Pcs Proform Exhaust Header Collector Gasket Engine Valve Cover One-Piece Holdown

Engine Valve Cover One-Piece Holdown Clamps

Fits Most 4 And 6 Cylinder Engines

Mini Digital Style

Same as 66291 hold-downs

This engine timing chain cover is manufactured from high quality steel material

Wedge-Locking Header Bolts Hex Head 3/8 Diameter X 3/4 Inch Blk Oxide 16 Pcs Proform Exhaust Header Collector Gasket Engine Valve Cover One-Piece HoldownEach 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