5.0 · 1 review
SKU: 66755

Wedge-Locking Header Bolts; M8, 1.181" Long, 12 Bolt Set

$34.99
FREE delivery
Description

ABOUT THIS PRODUCT

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.

Product Features:
  • Grade 8 (12.9) Steel
  • Hex Head Type
  • 1.181-inch Length
  • Fits GM LS Engines with 3/8-inch Wide Flange
Specifications
Brand
Proform (500)
SKU
66755
Product type
Automotive
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Returns Policy
Shipping Information

Free shipping on all orders. Most items ship next business day after your order is placed.

Returns Policy

Returns are accepted when the product is in its original, unopened container. Contact us if you have questions about your order.

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Customer Reviews

5.0

Based on 1 review

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C
Chris W. Verified Buyer
07/05/2025

Highly recommend

Good experience overall from checkout to delivery.

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