Mr. Gasket Black Oxide Header Bolts: Fits GM LS / Gen 3 Hemi / Ford Modular (91-15)

Mr. Gasket Header Bolts

1991–2015 GM LS Series, Gen 3 Hemi 5.7L–6.4L, Ford 4.6L–5.4L Modular Engines

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Overview:

Mr. Gasket Black Oxide Header Bolts are engineered for high-performance engine applications requiring reliable and space-efficient fasteners. Designed specifically for GM LS Series engines from 1997 to 2015, Gen 3 Hemi 5.7L to 6.4L engines from 2003 and up, and Ford 4.6L to 5.4L Modular engines from 1991 onward, these bolts provide a secure and durable connection for exhaust headers. Their compact hex head and flange design make them ideal for tight header flange spaces where traditional bolts may not fit.

These header bolts are perfect for enthusiasts and professional mechanics upgrading or replacing exhaust components on popular V8 platforms, ensuring a precise fit and long-lasting performance under high-heat conditions.

Key Features:

Mr. Gasket header bolts combine strength, fitment accuracy, and corrosion resistance to meet the demands of performance exhaust systems. Key features include:

• Black oxide finish for enhanced corrosion resistance and a sleek appearance
• Carbon steel construction for high tensile strength and durability
• Compact hex head design to maximize clearance in tight header flange areas
• Flanged head to distribute clamping force evenly and prevent flange damage
• Thread size: M8 x 1.25 with 25mm length, optimized for common header flange thicknesses
• Compatible with GM LS Series engines (1997–2015)
• Fits Gen 3 Hemi 5.7L, 6.1L, and 6.4L engines (2003 and newer)
• Suitable for Ford 4.6L and 5.4L Modular engines (1991 and newer)
• Includes a complete set of seventeen (17) bolts for full header installation

Construction & Design:

Crafted from high-quality carbon steel, these header bolts feature a black oxide coating that provides a balance of corrosion resistance and heat tolerance, essential for exhaust system components exposed to extreme temperatures. The compact hex head design allows installation in confined spaces without sacrificing torque capability, while the integrated flange ensures a secure seal and reduces the risk of header flange warping or damage during tightening.

The precise thread pitch and length are engineered to match OEM specifications for the targeted engine families, ensuring a reliable and consistent fit that maintains exhaust integrity and prevents leaks.

Installation & Fitment:

Installation is straightforward for anyone familiar with header or exhaust manifold work. The bolts are designed to fit directly into factory-style header flanges without modification. Their compact head profile allows for easier access in tight engine bays, reducing installation time and frustration. Always use proper torque specifications to avoid over-tightening and potential damage to the header flange or threads.

This set includes all the bolts needed for a complete header installation on the specified GM, Hemi, and Ford Modular engines, making it a convenient and reliable choice for performance upgrades or repairs.

What's Included:

• Seventeen (17) M8 x 1.25 x 25mm black oxide header bolts with compact hex heads and flanges

Ideal For:

These header bolts are ideal for automotive enthusiasts, mechanics, and performance builders working on GM LS Series engines (1997–2015), Gen 3 Hemi engines (2003 and newer), and Ford Modular 4.6L and 5.4L engines (1991 and newer). Whether upgrading exhaust headers, performing engine swaps, or replacing worn fasteners, Mr. Gasket header bolts provide a durable, space-saving solution that ensures a secure and leak-free exhaust connection.