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Proform Self-Locking Wedge Header Bolts 66755 Bolts, Hex Head, Steel, Nickel Plated, 8mm x 1.25, Chevy, 5.7, 6.0L, LS1, LS6, Set of 12

SKU: PRO66755

Header Fasteners

Proform Self-Locking Wedge Header Bolts 66755 Bolts, Hex Head, Steel, Nickel Plated, 8mm x 1.25, Chevy, 5.7, 6.0L, LS1, LS6, Set of 12

SKU: PRO66755

Header Fasteners
A$122.96
IN STOCK! Est Ship 4-7 days. In stock at 2 locations (more than 10 available)

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Description

Header Bolt - Locking - 8 mm x 1.25 Thread - 1.181 in Long - Hex Head - Steel - Nickel Plated - GM LS-Series - Set of 12


Data: v2 - Desc: v4.2 - Upd: 2026-11-08 14:13:56

Data: v4.2 - Upd: 2026-11-08 22:24:36

Features

Note for Australian and European Markets

Unless otherwise stated, this product may be engineered for use in Left-Hand Drive vehicles. Steering components, pedals, shifters, linkages, wing mirrors, instrument clusters, panhard rods/traction bars, drag links, brake boosters, brake or clutch lines, accelerator cables, heater cores, some master cylinders and adjacent parts can vary between LHD and RHD configurations. In some models compenents such as windscreen wiper arms, motors and linkages could differ in their size and orientation. Items such as floor mats & dash mats may have differences in their structure around the front row (or padding in different locations). In many cases items are identical depending on the design of the vehicle and part, but may have differing mounts, lengths or bolt patterns. Carefully review the product images and details to ensure suitability for your vehicle, or contact StreetFX support if you are unsure. Returns are not accepted for special order products.

(keyword: header)

Images are supplied by the manufacturer and may be generic. While all efforts are made to provide accurate pictures, there may be differences in the actual product, such as colour, quantity, version, or included components. Please carefully review the description and specifications for details on inclusions or any variations. Some items may be sold individually or in sets, and images may occasionally depict additional products or quantities not included in your purchase. For assistance or clarification, please contact customer support.

Specifications

Reference Information

Reference Data (Provide these details to our support team)
Brand Name/s Proform Parts, Proform
StreetFX SKU pro66755
SFX Item ID 5007192
Accounting SKU pro-66755
Manufacturer SKU 66755
Manufacturer UPC 037995667550
Alternative References 66755, PFM66755, PRO-66755

Header Bolts, Hex Head, Steel, Nickel Plated, 8mm x 1.25, Chevy, 5.7, 6.0L, LS1, LS6, Set of 12

Proform self-locking wedge header bolts get a grip on your headers that won't let go—until you're ready! These permanently assembled bolt sets feature special washers with super-hardened serrated teeth that, when torqued to 28 lbs.-ft., bite into and grab the bottom of the bolt head and the top surface of the header. Any bolt-loosening rotation is blocked by the wedge-locking action created by the washers' interfacing cams; but what's really impressive is that engine vibration—the enemy—increases the tension, making them even more secure! The bolts are re-useable and you can count on them to not fail. Proform self-locking wedge header bolts put an end to the constant tightening for a leak-free, headache-free future. They're available in different finishes and sizes for applications from 1965 and up.

Product Attributes
BrandProform Parts
Manufacturer's Part Number66755
Part TypeHeader Fasteners
Product LineProform Self-Locking Wedge Header Bolts
UPC037995667550
Fastener StyleBolt
Thread SizeM8 x 1.25
Head StyleHex
Underhead Length (in.)1.181 in.
Underhead Length (mm)30.00mm
Fastener MaterialSteel
Fastener ColorNickel plated
QuantitySold as a set of 12.

Compatibility

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