New Jeep Wrangler Cherokee 4.0L OHV Cylinder Head – Fits Casting Numbers # 0331, 0630, 7120

New Jeep 4.0L Inline 6 Cylinder Head – Reinforced Universal Casting (1991-2007)

Upgrade your Jeep’s legendary 4.0L engine with a reinforced, crack-resistant cylinder head designed to outperform the 0331, 7120, and 0630 factory castings.

The Jeep 4.0L inline-six is famous for its longevity, but factory heads are notorious for cracking between the #3 and #4 cylinders. Our premium aftermarket replacement features a thickened deck and reinforced water jackets to eliminate these common failure points. This universal casting is a direct “bolt-on” upgrade for all 4.0L Jeep engines from 1991 to 2007, whether your original head used a distributor or coil-pack ignition.

🛠️ 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. This ensures your oiling system remains uncontaminated from the first start-up.
• In-House Precision Machining: We perform all final machine work in-house, including precision valve seat cutting and guide sizing, to ensure perfect geometry and clearances.
• 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.
• Dimensional Inspection: Our technicians perform a multi-point inspection of the gasket-sealing surface. This ensures the head is perfectly flat and meets tight OEM tolerances for a flawless fit.
• 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: Jeep 4.0L Inline 6 (OHV)
• Year Range: 1991-2007
• Replaces Casting Nos: 0331, 7120, 0630
• Material: Heavy-Duty Cast Iron (Reinforced)
• Each Cylinder Head Includes: Valves and Springs Installed

🚛 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