Proform Blog

New Standard in Header Bolts from ProformĀ®Thursday, February 16, 2017

PROFORM® Grade 8 (or 12.9 Class) Header Bolts are permanently assembled with a set of special washers, that when sufficiently torqued to 28+ ft-lbs, blocks loosening rotational movement that might ordinarily loosen a standard bolt.

Each washer has super-hardened external serrated teeth that “bite” into and grip the bottom of the bolt head and the top surface of the header. The wedge-locking action created by the washers’ interfacing, matching cams prevents the bolt from loosening, and actually increases the wedge-locking tension, keeping the bolt secure. Because this simple wedge-locking method uses tension instead of friction, contact with oil actually facilitates the wedge effect. When changing headers, PROFORM Wedge-Locking Header Bolts can be untightened with a normal wrench, lubricated, and reused.

PROFORM’s simple and affordable solution to lock those headers up, doesn’t require pins and clips that fly around the garage, or adhesive fluids, allowing you to stop spending too much of your hard-earned money.

Each Wedge-Locking Set features:

  • Super-hard cam-locking washers that resist vibrating loose
  • No little clips or retainers to handle
  • Improved performance with oil
  • Reusability making them very economical


GM V8, S/B, LS

  • ......12 pcs, LS, .984” L x 8mm
  • ......12 pcs, LS, 1.181” L x 8mm

GM V6, S/B 265-400, Buick, Olds, Pontiac ’79 & earlier
Mopar B/B 383-440 (excp 413)
AMC V8’s

  • 66751…….12 pcs, ¾” L x 3/8”
  • 66753…….12 pcs, 1” L x 3/8”

GM B/B 396-502 (excp 348 & 409)
Ford 5.0L, S/B 289-302-351W
Mopar 413

  • 66752…….16 pcs, ¾ ”L x 3/8”
  • .......16 pcs, 1” L x 3/8”