New 6CT 8.3L 12V Cummins Cylinder Head – Precision Engineered with 21″ Air Intake

Upgrade your Cummins engine with the New 6CT 8.3L 12V Cummins Cylinder Head, designed for enhanced performance and durability. Specifically engineered for the Cummins 6CT 8.3L 12V engine, this cylinder head features a 21″ air intake opening, ensuring optimal airflow and engine efficiency. This is the ideal choice for those seeking to replace or upgrade their engine components to maintain peak performance. A core return is required for this purchase.

Key Features of the Cylinder Head:

• Superior Construction: Built from high-quality, robust materials, this cylinder head is designed to handle the toughest conditions, providing exceptional strength, wear resistance, and longevity.
• 21″ Air Intake for Maximum Airflow: Unlike other models with a 16″ air intake, this cylinder head features a 21″ air intake opening. The larger intake allows for significantly better airflow, enhancing combustion efficiency, power output, and overall engine performance.
• Precision Fit and Functionality: Manufactured to meet or exceed OEM standards, this cylinder head ensures a perfect fit for your Cummins 6CT 8.3L 12V engine, providing reliable performance and ease of installation.
• Optimized for Performance: The enhanced airflow provided by the 21″ intake leads to improved engine efficiency, reduced fuel consumption, and smoother operation, making it an excellent choice for heavy-duty applications.
• Versatile Application: Suitable for a variety of uses, including heavy-duty trucks, agricultural machinery, construction equipment, and industrial engines. This cylinder head is built to meet the demands of your most challenging jobs.
• Core Return Required

Applications:

• Cummins 6CT 8.3L 12V Engines
• Heavy-Duty Trucks
• Agricultural Equipment
• Construction Machinery
• Industrial Engines

Why the 21″ Air Intake Matters:

When it comes to optimizing your engine’s performance, the size of the air intake opening is crucial. The 21″ air intake on this cylinder head allows for greater airflow compared to the standard 16″ intake, leading to better combustion and enhanced engine power. This makes it the preferred choice for those looking to get the most out of their Cummins 6CT 8.3L 12V engine.

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!

Don’t Settle for Less:

Your engine deserves the best, and the with a 21″ air intake opening is engineered to deliver. Invest in this high-quality cylinder head to ensure your engine runs smoothly, efficiently, and powerfully for years to come.

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