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Cummins 8.3L Cylinder Head 1995-2005: OEM 3968930RX

CUMMINS 8.3L CYLINDER HEAD 1995-2005: OEM 3968930RX

Shipping ICON

ORDERS PLACED BEFORE 3PM EST WILL SHIP SAME DAY

WARRANTY ICON

WARRANTY
1M MILES OR 1 YEAR

$2,450.00

CORE CHARGE:

$500.00
iCORE DISCLAIMER: The CORE charge is a 30 day hold and will not be processed as long as the CORE is returned within 30 days. If you do not have a CORE or fail to return the CORE within 30 days, the CORE charge hold amount will be processed at that time.

AVAILABILITY IN STOCK
OEM NUMBER3968930RX
PART TYPECylinder Head
BRANDTamerx Diesel Products
ENGINE MAKECummins
ENGINE TYPE8.3L
YEAR1995-2005
PART NUMBER3968930RM

PRODUCT DESCRIPTION

This is a Remanufactured Tamerx Cylinder Head, Tamerx part number 3968930RM ( OEM Part Number 3968930RX ). All parts are proudly remanufactured in the U.S.A. to the highest of OEM standards, and improvements are often applied to the original design in the remanufacturing process. This part is primarily made for a Cummins 8.3L, production years 1995-2005, and comes with a One Million Miles or One Year Warranty. For additional warranty info Click Here

OEM NUMBERS

Primary OEM3968930RX
Additional OEM3904688, 3919764, 3920028, 3936154, 3968930RX, J917768, J925644, J968930, J991155

ADDITIONAL DETAILS

CONDITIONRemanufactured
UPC / Barcode00840490535718
WEIGHT225.00 LBS

SHIPPING OPTIONS

Ship Weight : 225.00 LBS
UPS Ground, 2nd Day Air, Next Day Air

SHIPPING POLICY

Tamerx Diesel Products ships via UPS Ground. Next day air shipping can be arranged for a reasonable price of anywhere from $50.00 - $100.00 depending on the weight of the product and your location. We will do everything we can to make sure that you get the service you need. We understand how important it is to receive your order as quickly as possible.
In most cases Tamerx Diesel Products only needs one address, as long as your product is shipping to the same location as your billing information. In order to eliminate credit card fraud, your billing information must match the credit card you provide.

The terms, conditions, and details of our warranty vary from product to product. Specific warranty details can be found below.

Tamerx Diesel Products provides a replacement warranty on all of our parts. The duration and mileage limitations of the warranty vary by product and are specified on the product's detail page/item listing.

Please note that the warranty covers replacement of the part and the cost of shipping the replacement part to you only. It does not cover any shop, labor, towing, or any similar or related costs. This is not a "money back guarantee".

If you experience a problem with your part or it is not functioning properly, the correct warranty procedure is to call us at (510) 257-1777 (8:00 AM - 5:00 PM ET Monday through Friday). Be sure to have your order number and/or other relevant order information ready so we can easily locate your order and resolve your issue as quickly as possible. From that point, we will review with you any troubleshooting steps that may need to be taken and other areas or systems that can be checked to rule out external problems contributing to your part's issue. If a replacement is determined to be necessary, we will then arrange for your replacement part to ship out ASAP and issue any necessary return shipping labels and/or documents.

As is the case for the majority of the diesel products sold on Tamerx Diesel Products, your part's warranty is active as soon as you install it. In some other cases, warranty activation is contingent upon you sending us your core (i.e., your old part). Tamerx Diesel Products will provide you a return shipping label for parts that have a warranty with a core return condition. When we have received your core return, the part's warranty coverage begins. We reserve the right to void the product warranty if your core is not received within the allotted time, or if it isn't received at all. If the warranty for the diesel part you are purchasing has a core return requirement, it will be clearly noted on the product detail page/item listing.

What is a Core Charge?

A core charge (also called "core deposit") is similar to the deposit you might pay for a can or bottle of soda and is a standard requirement in the auto parts industry. For example, in many states, to promote recycling, you pay a deposit when you purchase a can of soda and receive your deposit back when you return the empty can. Many automotive parts have a core charge, or core price, that works in essentially the same way as a soda can deposit.

30 Day Core Charge Hold

You authorize Tamerx Diesel Products, to hold your credit card for the specified core charge amount and that you agree to return your core with 30 days of receiving the purchased part. When we have received your core return, the hold is released and the core charge payment is canceled.

The customer, or parts buyer, is responsible for any shipping costs associated with core returns unless otherwise specified in the product listing/detail page. Tamerx Diesel Products offers prepaid UPS shipping labels (SKU numbers UPS-CR1 and UPS-CR2) for use in returning your core that are available for purchase on our website during your shopping/order process.

The shipping label you will need to use for the core return is dependent upon what part you are purchasing. UPS-CR1 is good for cores weighing up to 20 pounds. UPS-CR2 is appropriate for shipping cores weighing 21 pounds or more. You must include enough information with the core return that clearly identifies it as a.) a Core Return, and b.) contains enough information we can use to clearly associate the core return with your order. Including a copy of the invoice or packing slip that came with the original shipment, clearly marked "Core Return", is ideal. Alternately, you can include a note marked as "Core Return" that includes your order number, full name and address, and phone number or other contact information. Failure to include this information with your returned core will most likely delay any due core credit being issued and/or delay any applicable warranty activation. Core returns need to be for the exact part purchased and cannot be damaged. Substituting another part in place of the part you have purchased is not acceptable.

All fluids must be drained.

If you have purchased a set or a parts package, you will need to return cores for all components of the set. For example, if you have purchaed a high pressure oil pump with an IPR valve, you will need to return both HPOP and IPR valve cores to receive proper credit. If you have purchased an EGR cooler/EGR valve package, your core return must consist of an EGR cooler core and an EGR valve core, or core credit will not be given.

Core Charges are often mandated by state legislature, and, as such, the actual core charge and taxes on the charge may vary depending on the state in which you buy your part. The Tamerx Diesel Products core charge presented to you online today with your item is representative of the most common core charge.


Installed on Cummins 8.3L engines from model years 1995–2005, OEM 3968930RX is a cylinder head designed to meet factory specifications for proper engine operation. This component is manufactured to ensure accurate fitment and compatibility with existing engine assemblies. Built from durable materials, it is suited for the operating stresses and temperatures common in heavy-duty diesel applications. The cylinder head supports controlled airflow, effective combustion chamber sealing, and proper valve function during normal engine operation. It is a reliable option for maintenance and targeted repair needs requiring consistent engine system performance.

FITMENT CHART

YEARMAKEENGINE(S)
1995Cummins 8.3L
1996Cummins 8.3L
1997Cummins 8.3L
1998Cummins 8.3L
1999Cummins 8.3L
2000Cummins 8.3L
2001Cummins 8.3L
2002Cummins 8.3L
2003Cummins 8.3L
2004Cummins 8.3L
2005Cummins 8.3L

PEOPLE ALSO ASKS | BLOG(S)

The Cummins 8.3L Cylinder Head 1995–2005: OEM 3968930RX works as the upper structural component of the engine, sealing the combustion chambers and housing critical valvetrain and fuel system components. It sits directly on top of the engine block and forms the top portion of each cylinder.

During engine operation, the pistons move upward to compress air inside the cylinders. The cylinder head, along with the head gasket, seals this high-pressure environment so combustion can occur safely and efficiently. When fuel is introduced and ignites, the expanding gases push the piston downward, generating the force that drives the engine.

The cylinder head also manages airflow into and out of the engine. It contains intake and exhaust ports that allow fresh air to enter and burned gases to exit. Valves housed within the head open and close at precise intervals, controlled by the camshaft and valvetrain components.

Here’s how it functions within the engine:

  • Seals the combustion chamber against extreme pressure
  • Houses intake and exhaust valves for airflow control
  • Supports injector mounting and fuel delivery
  • Circulates coolant through internal passages to regulate temperature

OEM 3968930RX is engineered specifically for Cummins 8.3L engines from 1995–2005, ensuring proper alignment, sealing, and durability. Its correct operation is essential for maintaining compression, managing heat, and supporting reliable engine performance.

When your cylinder head is failing, immediate diagnosis is critical to prevent severe engine damage. A failing cylinder head can lead to compression loss, coolant intrusion, overheating, and internal engine wear if not addressed quickly.

The first step is to confirm the source of the problem. Symptoms such as overheating, white exhaust smoke, coolant loss, rough running, or milky engine oil may indicate head gasket failure, cracking, or warping. A compression test, leak-down test, and cooling system pressure test can help determine the extent of the damage.

Midway through diagnosis, focus on these essential checks:

  • Inspect for coolant mixing with engine oil
  • Check for combustion gases in the cooling system
  • Perform compression and cylinder leak-down testing
  • Inspect spark plugs or injectors for coolant contamination
  • Check for external coolant leaks around the head
  • Monitor engine temperature and cooling system performance

If testing confirms a warped or cracked cylinder head, removal is required for inspection and possible resurfacing or replacement. Minor warping may be corrected through machining, but cracks or severe distortion typically require full replacement.

Before reinstalling or replacing the cylinder head, correct the root cause of the failure. Overheating from a failed thermostat, water pump, radiator restriction, or injector over-fueling can quickly damage a new head. Proper cooling system repair, torque procedures, and gasket installation are essential to restoring reliable engine performance and preventing repeat failure.

It interfaces with the intake manifold, exhaust system, valvetrain, and cooling passages.

Yes, it must be installed with the correct head gasket to ensure a proper seal with the engine block.

Yes, warpage or cracks can lead to compression loss and related engine issues.

Yes, precision-machined valve seats are part of the head assembly.

Cummins Cylinder Heads