New Jeep 4.0L OHV Cylinder Head – Fits Casting Numbers # 0331, 0630, 7120 W/ Head Gasket Set & Bolts, Water Pump & Timing Set, Full Pushrod & Rocker Arm Set

New Jeep 4.0L OHV Cylinder Head – Fits Casting # 0331, 0630, 7120 w/ Gasket Set, Bolts, Water Pump, Timing, Pushrods & Rockers

The ultimate engine refresh kit for your Jeep 4.0L: A reinforced, crack-resistant cylinder head bundled with a head gasket set, bolts, water pump, timing set, 12 pushrods, and a full rocker arm assembly.

The Jeep 4.0L inline-six is a legend, but factory heads—particularly the 0331—are notorious for cracking. Our premium aftermarket replacement features a thickened deck and reinforced water jackets specifically engineered to eliminate these common failure points. This universal design is a direct bolt-on for all 4.0L engines from 1991 to 2007, providing a permanent solution for your Cherokee, Wrangler, or Grand Cherokee.

🛠️ In-House Machining Process

• Debris-Free Preparation: Every new casting is chemically cleaned and blown out to remove all residual machining oils and manufacturing debris, protecting your oiling system from start-up.
• In-House Precision Machining: Final machine work is performed in-house, including precision valve seat cutting and guide sizing for perfect geometry and clearances.
• Pressure & Integrity Testing: We pressure-test every head to 60 PSI to verify that the casting is 100% free of porosity leaks or internal defects.
• Dimensional Inspection: Surfaces are verified for perfect flatness, ensuring a flawless gasket seal that meets tight OEM tolerances.
• Professional Assembly: Valvetrain components are installed and verified in a clean-room environment. We check spring heights and seal seating to ensure the assembly is ready for immediate use.
• Vacuum-Seal Verification: Every port undergoes Vacuum Testing to guarantee a 100% airtight seal between valves and seats for maximum compression.

📊 Technical Specifications

• Engine: Jeep 4.0L Inline 6 (OHV)
• Year Range: 1991-2007
• Replaces Casting Nos: 0331, 7120, 0630
• Material: High-Strength Reinforced Cast Iron
• Each Cylinder Head Includes: Valves and Springs Installed
• Additional Hardware: Head Gasket Set, Head Bolt Set, Water Pump, Timing Set, 12 Pushrods, and Full Rocker Arm Set

🚛 Fitment Data

Common Applications:

• Jeep Wrangler (YJ/TJ/LJ): 1991-2006
• Jeep Cherokee (XJ): 1991-2001
• Jeep Grand Cherokee (ZJ/WJ): 1993-2004
• Jeep Comanche (MJ): 1991-1992