3925400 | Cummins 6BT 12V 5.9L New Cylinder Head +60lb Performance Springs

Cummins 6BT 12V 5.9L Reinforced New Cylinder Head – Loaded & Complete

Redesigned Aftermarket Casting with Higher Nickel Content to Eliminate Cracking

Engineered for the legendary Cummins 5.9L 12-Valve (6BT) turbo-diesel series, this brand-new, heavy-duty aftermarket cylinder head is the definitive solution for high-mileage restoration and performance builds. Unlike standard replacement castings, this “reinvigorated” design features reinforced internal coolant jackets and thickened walls in critical, crack-prone areas—specifically around the valve seats and injector bores—to provide superior structural integrity under high-boost and high-EGT (Exhaust Gas Temperature) conditions.

Utilizing a premium cast iron alloy with an increased nickel content, this cylinder head offers enhanced thermal resistance and dimensional stability compared to original equipment (OE) castings. Each unit is precision-machined to exact tolerances, ensuring a superior head gasket seal and optimal volumetric efficiency for your ISB/6BT platform. Whether you are maintaining a heavy-duty Ram 2500/3500 or a specialized industrial application, this reinforced casting is bred for extreme duty cycles and built to outlast both OEM and conventional aftermarket alternatives.

🛠️ Heavy Duty Build & Components

• Reinforced Casting: Redesigned to address common 6BT flaws like premature cracking.
• Nickel Content: Higher nickel concentration in the cast iron for maximum durability.
• Loaded Assembly: Fully loaded with valves, springs, retainers, and valve locks.
• Viton Seals: Includes new high-temperature Viton valve stem seals.

🛠️ 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 Type: Cummins 6BT 12V (5.9L Diesel)
• Casting Number: 3925400
• Year Range: 1989–1998
• Configuration: 6-Cylinder, Loaded Assembly
• Condition: Brand New – Reinforced Aftermarket Casting
• Each Cylinder Head Includes: Valves and Springs Installed

🚛 Fitment Data

Common Applications:

• Dodge Ram 2500/3500: 1994–1998 (5.9L 12V Diesel)
• Dodge Ram 250/350: 1989–1993 (5.9L 12V Diesel)
• Case/Industrial: Various 6BT 5.9L applications