Company: Proform/Specialty Auto Parts
Click on a thumbnail to see the full-size image
Locking Header Bolts
System Prevents Rotational Movement of the Bolt with Wedge-Locking Tension Created by the Two Washers' Interfacing Cams
These wedge locking header bolts solve the constant problem of header
bolts vibrating loose without the aid of any cumbersome wires, pins, clips,
adhesives, or special tools. This 12-piece set of 1-inch header bolts (#66753)
covers GM V6, 265-400 small-block, Buick, Olds, Pontiac (’79 and earlier),
Mopar big-blocks 383-440 (Except 413) and AMC V8s using 3/8-inch bolts. ¾-inch
length is also available in 12 and 16-piece sets (#66751, #66752 respectively)
and are commonly used for cast iron heads, where these 1-inch length bolts are
recommended for aluminum heads.
These PROFORM header bolts are assembled
using a set of factory installed super hard wedge-locking washers, so there are
no additional components. Once correctly torqued, the washers’ serrated teeth
grip the bottom of the bolt head and the top surface of the header flange. This
system prevents rotational movement of the bolt due to the wedge-locking
tension created by the two washers interfacing cams. Engine vibration actually increases the wedge locking tension,
keeping the bolt secure. When removing the headers, these PROFORM header bolts
can be un-tightened with a normal wrench. To view a video of how these unique
bolts work visit http://youtu.be/mmZg-pLdds .
For additional information and a 2013 catalog full of new
licensed performance, dress-up and vehicle enhancement parts and accessories
for Chevrolet and Ford vehicle, visit www.ProformParts.com or call 586-774-2500, Fax: 586-778-7775.