New Complete Pair GM GMC Chevrolet 6.6L OHV Duramax Diesel LMM Cylinder Heads 2006-2010 W/ Head Gasket Set & Bolts, Water Pump & Timing Set

Upgrade your Duramax 6.6L LMM engine with this New Pair of LMM Duramax Cylinder Heads, now bundled with timing kits and a water pump for a complete engine refresh. Whether you’re replacing worn-out heads or enhancing performance, this all-in-one solution ensures efficiency, durability, and reliability for heavy-duty applications.

Premium Quality & OEM Fitment

Crafted to meet and exceed OEM standards, these cylinder heads are precision-engineered for a seamless fit with your Duramax engine. Designed for optimal airflow, they help maximize power output, fuel efficiency, and engine longevity, making them ideal for towing, hauling, and daily use.

Why Choose LMM Duramax Cylinder Heads?

• Complete Engine Solution: Includes cylinder heads, head gasket & bolts, timing kits, and a water pump for a hassle-free installation and optimal performance.
• Enhanced Durability: Built from high-quality materials to withstand extreme temperatures and pressures in heavy-duty applications.
• Optimized Airflow for Performance: Improved intake and exhaust flow for better horsepower, throttle response, and fuel economy.
• Direct OEM Replacement: No modifications required – install with confidence and minimize downtime.
• Perfect for Heavy-Duty Use: Designed for towing, hauling, off-road, and high-performance applications.

Key Features:

• High-strength construction for maximum reliability and longevity
• Enhanced airflow for increased power and efficiency
• Complete kit includes timing kits and a water pump for a full engine refresh
• Direct fit for easy installation with no modifications needed
• Ideal for demanding applications, ensuring peak engine performance
• Core Return Required

Heavy Duty Parts Company – Core Returns Policy

Effective December 17, 2025

At Heavy Duty Parts Company, core returns are essential to our ability to provide high-quality, cost-effective cylinder heads. Returned cores supply critical components—such as keepers, springs, and retainers—that are vital to proper engine performance and allow us to maintain OEM-level quality.

No Upfront Core Charge

Unlike many suppliers, we do not charge a core fee upfront. Instead, we rely on customers to return their used cores within the required timeframe.

Core Return Requirements

• Cores are due within 30 days of the purchase date

• If a core is not returned within 60 days, the product warranty is void

• Unreturned cores will be charged as follows:

  • Cylinder heads under $600: $200 per unreturned core

  • Cylinder heads $600 and above: $400 per unreturned core

Customers needing additional time may contact us to request an extension. Approved extensions will prevent core charges from being applied.

Core Return Process

Cylinder heads are shipped with prepaid core return labels included in packets attached to the outside of each box. If labels are missing, customers should contact us for replacements prior to returning the core.

Core Eligibility

Some cylinder heads do not require a core return. In certain cases, core requirements may be waived at our discretion.

Why Core Returns Matter

• Reused core components help maintain OEM-quality standards

• Core returns allow us to keep pricing competitive

• Recycling cores supports sustainability by reducing waste and conserving resources

This policy applies to all purchases made on or after December 17, 2025.

Send Back All Components

To ensure the quality and integrity of our remanufacturing process, we ask that you return all components that were originally included with your new cylinder head. This includes items such as:

• Rocker arms
• Camshafts (if applicable)
• Any other hardware that came with your purchase

Easy & Free Core Return Process

• Each purchase includes a prepaid core return label in a plastic sleeve on the box.
• Simply pack your core with all included components, attach the label, and drop it off with the carrier—no extra cost to you.
• Returned cores undergo inspection and recycling, ensuring maximum efficiency.

Customer Partnership & Sustainability

By returning your core and its components, you help maintain a reliable supply chain, ensuring we can continue offering top-quality products at the best prices. This process not only benefits your wallet but also contributes to a greener and more efficient automotive industry.

We appreciate your support in keeping our business and the industry running smoothly!

Upgrade your 6.6L diesel engine with this New Pair of LMM Duramax Cylinder Heads to boost your engine’s performance, durability, and efficiency. Whether you’re looking for an OEM replacement or an upgrade that delivers real-world benefits, these cylinder heads provide everything you need for long-lasting, reliable performance.

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