New Complete Pair GM GMC Chevrolet 6.6L OHV Duramax Diesel LMM Cylinder Heads 2006-2010

When it comes to maintaining or upgrading your Duramax engine, choosing the right cylinder heads can make all the difference. This New Pair of LMM Duramax Cylinder Heads is designed to provide superior performance, durability, and reliability for your 6.6L diesel engine. Whether you’re facing worn-out heads or looking for an upgrade that enhances engine efficiency, these cylinder heads are the perfect solution.

Constructed to meet and exceed OEM standards, these cylinder heads are built with precision and attention to detail, ensuring a seamless fit with your Duramax engine. Optimized for better airflow, they help improve power output and fuel efficiency, making them ideal for towing, hauling, or heavy-duty work. Their high-quality construction also ensures that they can withstand the intense pressures and temperatures generated by diesel engines, offering long-lasting performance.

Why Choose LMM Duramax Cylinder Heads?

1. Superior Durability:
   These cylinder heads are engineered from high-quality materials to handle the extreme conditions of heavy-duty use. Designed for long-term durability, they ensure that your engine performs reliably in both daily driving and demanding applications. Whether it’s high temperatures or intense pressure, these heads will keep your engine running smoothly.
2. Improved Airflow for Enhanced Performance:
   The LMM Duramax Cylinder Heads are designed to optimize air intake and exhaust flow, resulting in more efficient combustion. This increased airflow can lead to better throttle response, more horsepower, and improved fuel economy. Whether you’re hauling, towing, or driving off-road, these cylinder heads will maximize your engine’s potential.
3. Direct OEM Replacement:
   Designed as a direct fit for the LMM Duramax engine, these cylinder heads are easy to install and require no modifications. This means you can quickly replace your old or damaged heads and get your truck back on the road with minimal downtime.
4. Perfect for Heavy-Duty Applications:
   Whether you’re using your Duramax for towing, heavy hauling, or everyday driving, these cylinder heads are built to handle the toughest jobs. They’re ideal for anyone looking to maintain peak performance and reliability in their truck, even under the most demanding conditions.

Key Features of LMM Duramax Cylinder Heads:

• High-quality construction for enhanced durability and reliability
• Improved airflow for better engine efficiency, power, and fuel economy
• Direct fit for seamless installation without modifications
• Optimized for heavy-duty applications, making it perfect for towing, hauling, and off-road use
• Core Return Required

Fitment Data:

EXPRESS 2500 VAN 06 8-403 (6.6L, Duramax diesel);
EXPRESS 2500 VAN 07 8-403 (6.6L, Duramax diesel); VIN 6 (8th digit, opt LMM)
EXPRESS 2500 VAN 08-10 8-403 (6.6L, Duramax diesel);
EXPRESS 3500 VAN 06 8-403 (6.6L, Duramax diesel);
EXPRESS 3500 VAN 07 8-403 (6.6L, Duramax diesel); VIN 6 (8th digit, opt LMM)
EXPRESS 3500 VAN 08-10 8-403 (6.6L, Duramax diesel);
SAVANA 2500 VAN 06 8-403 (6.6L, Duramax diesel);
SAVANA 2500 VAN 07 8-403 (6.6L, Duramax diesel); VIN 6 (8th digit, opt LMM)
SAVANA 2500 VAN 08-10 8-403 (6.6L, Duramax diesel);
SAVANA 3500 VAN 06 8-403 (6.6L, Duramax diesel);
SAVANA 3500 VAN 07 8-403 (6.6L, Duramax diesel); VIN 6 (8th digit, opt LMM)
SAVANA 3500 VAN 08-10 8-403 (6.6L, Duramax diesel);
SIERRA 2500 PICKUP 06 6.6L
SIERRA 2500 PICKUP 07 classic style (creased door skin), 6.6L, VIN 6 (8th digit, opt LMM)
SIERRA 2500 PICKUP 07 classic style (creased door skin), 6.6L, VIN D (8th digit, opt LBZ)
SIERRA 2500 PICKUP 07 new style (smooth door skin), 6.6L
SIERRA 2500 PICKUP 08-10 6.6L
SIERRA 3500 PICKUP 06 6.6L
SIERRA 3500 PICKUP 07 classic style (creased door skin), 6.6L, VIN 6 (8th digit, opt LMM)
SIERRA 3500 PICKUP 07 classic style (creased door skin), 6.6L, VIN D (8th digit, opt LBZ)
SIERRA 3500 PICKUP 07 new style (smooth door skin), 6.6L
SIERRA 3500 PICKUP 08-10 6.6L
SILVERADO 2500 PICKUP 06 6.6L
SILVERADO 2500 PICKUP 07 classic style (creased door skin), 6.6L, VIN 6 (8th digit, opt LMM)
SILVERADO 2500 PICKUP 07 classic style (creased door skin), 6.6L, VIN D (8th digit, opt LBZ)
SILVERADO 2500 PICKUP 07 new style (smooth door skin), 6.6L
SILVERADO 2500 PICKUP 08-10 6.6L
SILVERADO 3500 PICKUP 06 6.6L
SILVERADO 3500 PICKUP 07 classic style (creased door skin), 6.6L, VIN 6 (8th digit, opt LMM)
SILVERADO 3500 PICKUP 07 classic style (creased door skin), 6.6L, VIN D (8th digit, opt LBZ)
SILVERADO 3500 PICKUP 07 new style (smooth door skin), 6.6L
SILVERADO 3500 PICKUP 08-10 6.6L

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.

Order Your LMM Duramax Cylinder Heads Today!

Ensure consistent power and performance. Purchase your cylinder head today and drive with peace of mind!

Shop

Complete Guide to Every Line of Duramax Engines

Duramax