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Replacing exhaust header bolts might seem like a minor task, but using the correct hardware is crucial for a secure and leak-free exhaust system. Inferior or incorrect bolts can lead to premature failure, exhaust leaks, and potentially costly damage to your vehicle. Investing in high-quality replacement bolts ensures longevity and optimal performance for your automotive exhaust.
OEM Number: The OEM part numbers for our exhaust manifold bolts is 551696, can be used to replace lost or broken and worn out manifold bolts. Please check the OEM, brand, model, and year carefully in advance to avoid the product being unusable
Suitable Vehicles: Our exhaust bolts are compatible with GM 1997-2024 LS LT series engines, compatible with Chevrolet 1999-2015 Tahoe, 2015 Suburban, and more. Please refer to the details page for more specific information on the applicable models
Product Size: Our packet includes 12 exhaust manifold bolts with the size of 1.28*0.66*0.66''. The thread size is M8x1.25, threaded part is 0.98'' long and 0.30'' wide, the diameter of hexagonal head is 0.39'', please do careful check the size in advance
Enhanced Strength and Security: Featuring a reinforced construction, these LS header bolts keep a secure connection between the exhaust manifold and the engine block, minimizes vibrations of manifold avoid the problem of insufficient turbocharging
3/8"-16 x 1.00", 12 point head bolts for use with Small Block Chevrolet, Big Block Chevrolet, Small Block Ford, Small Block Chrysler and Big Block Chrysler thick flange header applications Heat treated Grade 8 bolts with black oxide finish 16 pieces
Material : This exhaust bolt is made of carbon steel and its surface is treated with color galvanization. It is sturdy in texture, has excellent impact resistance, is wear-resistant and durable, can withstand high temperature and high pressure, and is not...
Anti-slip design : The hexagonal outer design of the product provides excellent grip, effectively preventing slipping during installation and disassembly. Meanwhile, the hexagonal head is compatible with standard wrenches and sockets, facilitating torque...
Features : The bolts are processed with advanced techniques, by integrating the bolts and washers into one, time is saved. The serrated bottom surface of the flange enhances the anti-loosening performance. The smooth and uniform threads ensure quick and...
Wide application : This automotive exhaust manifold bolt kit can be applied to various automotive exhaust systems or other components that require high-strength fixation. It can also be used in metal frames, wood structures, and electrical enclosures in...
【Compatiable With】-- GM Chevrolet Chevy LS1 LS3 LS2 LSX LT Engines 551696 Bolt, Fits all GM LS & LT series engines 1997-up.
【Replace NO.】--551696.
【Material】--10.9 bolts，Exhaust Manifold Bolts Kit is heavy-duty, high-strength, and galvanized, with the addition of a special black coating, which will provide long-lasting corrosion protection against thread seizure.
【Package Includes】--12* M8-1.25 x 25mm Exhaust Manifold Bolts .
12PCS COMPLETE HEADER BOLT KIT. This set includes 12 premium exhaust manifold/header flange bolts with integrated flanged heads—no need for extra washers. Designed to meet JIS specifications for precise fit and secure installation.
Compatibility: Directly replaces OEM Part Number 551696. This header bolt kit is engineered for LS Series engines, including LS1, LS2, LS3, LS6, LSX, LM7, LR4, LQ4, LQ9, L33, LH6, L92, L76, L99, L96, L82, L83, L84, L86, L87, and LT1 models.
GRADE 10.9 HIGH-STRENGTH STEEL. Each bolt is manufactured from heavy-duty alloy steel with a Grade 10.9 rating—built to withstand extreme torque, vibration, and heat for long-lasting, secure performance.
ADVANCED DACROMET COATING. Coated with Dacromet for superior corrosion resistance in high-moisture, salt-spray, and high-heat environments. The eco-friendly coating prevents rust without the risk of hydrogen embrittlement.
【Compatible vehicle】SBC Header Bolt Kit compatible with Chevrolet Bel Air Suburban Corvette Truck C10 Pickup C20 C30 Suburban C40 C50 Caprice Corvette Chevy II Impala K10 Pickup K20 Pickup Panel Suburban Malibu C1500 C2500 Camaro Caprice Express...
【Included】Includes 12 sets stainless steel 3/8-16×1" bolts and washers for exceptional corrosion resistance—unlike chrome or carbon steel bolts, these will not rust or seize
Last update on 2026-10-15 / Affiliate links / Images from Amazon Product Advertising API
How to Choose the Best Automotive Replacement Exhaust Header Bolts
Understanding Bolt Materials
Stainless Steel: Offers excellent corrosion resistance, making it ideal for harsh engine bay environments. It's durable and can withstand high temperatures.
High-Carbon Steel: Often heat-treated for increased strength and durability. While strong, it may be more susceptible to rust than stainless steel if not properly coated.
Alloy Steels: These can offer superior strength and heat resistance, often used in high-performance applications. Ensure they have appropriate coatings for corrosion protection.
Bolt Size and Thread Pitch
Diameter: Measure the original bolt or the hole in your manifold and gasket to determine the correct diameter. Common sizes include M6, M8, and M10.
Length: The bolt needs to be long enough to securely fasten the header or manifold to the cylinder head without bottoming out. Measure the thickness of the components being joined.
Thread Pitch: This refers to the spacing and size of the threads. Using the wrong thread pitch will prevent the bolt from engaging properly or stripping the threads in the cylinder head. Consult your vehicle's service manual for specifications.
Head Style and Strength Grade
Head Style: Common styles include hex head, flange head, and socket head. Flange heads offer a wider bearing surface, distributing pressure more evenly.
Strength Grade: Bolts are graded to indicate their tensile strength. Higher grades (e.g., Grade 8 or Class 10.9) are stronger and better suited for high-stress, high-temperature exhaust applications.
Frequently Asked Questions
Why do exhaust header bolts need to be replaced?
Exhaust header bolts are subjected to extreme heat cycles and vibrations, which can cause them to stretch, weaken, or break over time. Replacing them ensures a secure seal and prevents exhaust leaks.
Can I use regular hardware store bolts?
It's generally not recommended. Automotive exhaust header bolts are made from specialized materials designed to withstand high temperatures and corrosive environments. Regular bolts may fail prematurely under these conditions.
What is the difference between header bolts and manifold bolts?
While the terms are often used interchangeably, header bolts are specifically designed for aftermarket exhaust headers, which can have different mounting requirements. Manifold bolts are for OEM exhaust manifolds. Always check compatibility with your specific exhaust component.
How do I know what size bolts I need?
The best way is to consult your vehicle's service manual for the exact specifications. You can also measure the diameter and length of the existing bolts or the threaded holes in your cylinder head.
Do I need special washers?
Yes, it's often recommended to use hardened washers, especially with higher-grade bolts. These washers help distribute the load evenly and prevent the bolt head from damaging the surface of the exhaust component.
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