New Pair Loaded Duramax 6.6L GM Chevrolet Silverado Sierra Cylinder Heads LLY | No Core Required

New Pair Loaded Duramax 6.6L GM Chevrolet Silverado Sierra LLY Cylinder Heads

OEM-Quality Replacement Engineered for Heavy-Duty Performance

Enhance the reliability of your GM 6.6L Duramax engine with this brand-new pair of loaded LLY cylinder heads. Specifically engineered for Silverado and Sierra models, these heads feature a reinforced aftermarket casting designed to exceed OEM specifications and resist cracking under high pressure. Each head comes fully assembled with premium valves, springs, and retainers, providing a direct-fit solution that ensures long-lasting durability and peak engine efficiency.

🛠️ In-House Machining Process

• Debris-Free Preparation: Every new casting is chemically cleaned and blown out to remove all residual machining oils, metal shavings, and manufacturing debris. This ensures your oiling system remains uncontaminated from the first start-up.

• In-House Precision Machining: Unlike “shelf-stock” heads, we perform all final machine work in-house. This includes final guide sizing and precision valve seat cutting to ensure perfect geometry and clearances before the head reaches the assembly bench.

• Pressure & Integrity Testing: To go beyond the factory standard, we pressure-test every head to 60 PSI. This verifies that the casting is free of porosity leaks or internal defects that could compromise the cooling or oiling systems.

• Dimensional Inspection: Our technicians perform a multi-point inspection of the gasket-sealing surface and bore alignment. This ensures the head is perfectly flat and meets tight OEM tolerances for a flawless fit.

• Professional Assembly & Setup: Valvetrain components are installed and verified in a clean-room environment. We check spring heights and seal seating to ensure the assembly is balanced and ready for high-performance use.

• Vacuum-Seal Verification: Every intake and exhaust port is Vacuum Tested. This guarantees a 100% airtight seal between the valves and seats, ensuring maximum compression and peak performance right out of the box.

📊 Technical Specifications

• Engine Size: 6.6L
• Engine Code: LLY
• Condition: Brand New Aftermarket
• Components: Fully Loaded with Valves, Springs, and Retainers
• Quantity: Pair
• No Core Return Required

🚛 Fitment Data

Common Applications:

• GMC Sierra 2500: 2004–2005 GMC Sierra 2500 (6.6L, VIN 2 (8th digit))
• GMC Sierra 3500: 2004–2005 GMC Sierra 3500 (6.6L, VIN 2 (8th digit))
• Chevrolet Silverado 2500: 2004–2005 Chevrolet Silverado 2500 (6.6L, VIN 2 (8th digit))
• Chevrolet Silverado 3500: 2004–2005 Chevrolet Silverado 3500 (6.6L, VIN 2 (8th digit))