Product was as described and packaged well! Communication throughout prosses was also great! I will definitely be using them in the future with other projects.
Parts arrived as promised. Ported heads gave me that low end torque and high rev HP I was looking for! ...if only I did the cam at the same time.
It's hard to believe no one has reviewed these guys yet. Very professional and detailed company it was a pleasure doing business with you. The answered the phone every time I called or answered every email in a timely manner! I will definitely use them for all my cylinder head needs moving forward. Thank again!
Part came in and work as a champ. Price was better than all other places I look for the set. Will recommended to all my soldiers and/or buddies if they need cylinder heads replace. Thank you guys.
3943627 | Cummins ISB 24V 5.9L Loaded Complete Reinforced New Cylinder Head | 5361587
$1,695.00
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Additional Info
New Cummins ISB 24V 5.9L Loaded Complete Reinforced Cylinder Head (Casting 3943627 / 5361587)
Premium Heavy-Duty Replacement — Fully Loaded & Ready to Install
Upgrade your engine with this brand new, fully loaded complete reinforced cylinder head designed specifically for Cummins ISB 24V 5.9L applications. Engineered as a direct OEM replacement, this heavy-duty aftermarket casting features increased internal wall thickness and higher nickel content to prevent cracking and premature valve train failure. It arrives pre-assembled with premium components for a seamless, immediate installation that restores long-term reliability to your vehicle.
🛠️ 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 engine’s 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.
- 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 system.
- 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.
- Professional Assembly & Setup: Valvetrain components are installed and verified in a clean-room environment. Each head comes fully assembled with valves and springs, ready for a direct bolt-on installation.
- 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 right out of the box.
📊 Technical Specifications
- Engine Size: 5.9L
- Valves: 24V
- Casting Numbers: 3943627, 5361587
- Condition: Brand New
- Material: Heavy-Duty Reinforced Cast Iron
- Configuration: Complete / Fully Loaded Assembly
- OEM Replacement #: 3942628, 3943627, 3943628, 3943892, 3944991, 3944992, 3944993, 3944994, 3944995, 3945524, 3946202, 3937729, 3957403, 3990135, 3991771, 3991772, 3991773, 5361587
- Core Return Required
🚘 Common Applications
Direct fit for Cummins ISB 24V 5.9L engines found in:
- Years: 1998–2003
- Fitment: Fits both electronic and non-electronic variations of the 24-valve 5.9L Cummins ISB turbo diesel motor.
- Vehicle & Equipment Types: Light/Heavy Duty Trucks, Medium Duty Commercial Vehicles, and Industrial Equipment.
📦 Core Return & Warranty
- Core Process: No upfront core fee. Receive your new head and compare it to your original before installation. Once complete, use the pre-paid return label included in your shipment. Cores must be returned within 30 days. Click here for Core Policy.
- Warranty: Includes a 2-Year Warranty covering defects in materials and workmanship. Click here for Warranty details.
Dedicated to Customer Satisfaction
What sets us apart from the competition is our dedication to customer satisfaction. We strive to make your shopping experience as seamless and convenient as possible. Our user-friendly online platform allows you to browse our comprehensive inventory, compare products, and place orders with ease. With secure payment options and swift shipping, you can trust that your order will arrive promptly, minimizing downtime and maximizing productivity.





