New Pair Mercruiser 7.4L 454 Marine Cylinder Heads – Cast Iron Casting # 279 W/ Head Gasket Set and Bolts

New Pair MerCruiser 7.4L 454 Marine Cylinder Heads – Cast Iron Casting #279 w/ Head Gasket Set & Bolts

Premium OEM-Quality Marine Replacement Kit with Gaskets and Bolts

This is a new pair of cast iron cylinder heads for MerCruiser 7.4L 454 marine engines, featuring casting number 279. The set comes fully assembled and includes a complete head gasket set and high-strength head bolts for a streamlined installation. Engineered specifically for marine environments, these heads offer superior resistance to corrosion and thermal stress.

🛠️ 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

• Product Type: Pair of Marine Cylinder Heads
• Engine Size: 7.4L (454 CID)
• Casting Number: 279
• Material: Heavy-Duty Cast Iron
• Condition: New
• Included Components: Fully assembled heads (valves and springs installed), head gasket set, and cylinder head bolts

🚛 Fitment Data

Common Applications:

• Chevrolet 2500 Pickup: 1996–2000 Chevrolet 2500 Pickup (8-454 (7.4L))
• Chevrolet 30 Van: 1996 Chevrolet 30 Van (8-454 (7.4L)) 30 HD
• Chevrolet 3500 Pickup: 1996–2000 Chevrolet 3500 Pickup (8-454 (7.4L))
• Chevrolet Express 3500 Van: 1996–2000 Chevrolet Express 3500 Van (8-454 (7.4L))
• GMC 2500 Pickup: 1996–2000 GMC 2500 Pickup (8-454 (7.4L))
• GMC 3500 Pickup: 1996–2000 GMC 3500 Pickup (8-454 (7.4L))
• GMC 3500 Van: 1996 GMC 3500 Van (8-454 (7.4L)) 3500 HD
• GMC Savana 3500 Van: 1996–2000 GMC Savana 3500 Van (8-454 (7.4L))
• Chevrolet Suburban 2500: 1996–1999 Chevrolet Suburban 2500 (8-454 (7.4L))