Product Description
The Cummins 4089650 OEM Upper Engine Gasket Kit (.010 Oversize) is a complete top-end OEM gasket solution engineered for 1989–1998 5.9L 12-Valve Cummins 6BT engines requiring an oversize head gasket. This kit includes all major upper-engine sealing components needed when servicing the cylinder head, valve train, intake/exhaust manifolds, and related systems. The .010" oversize specification ensures proper sealing when cylinder head or block surfaces have been machined during rebuild.
Using a genuine Cummins gasket kit guarantees OE-grade materials, correct thickness, and long-term reliability under high cylinder pressures—far superior to aftermarket alternatives. Perfect for stock, towing, fleet, and performance applications where OEM durability matters.
Fitment
- 1989–1998 Dodge Ram 2500/3500 with 5.9L 12-Valve Cummins (6BT)
- All 5.9L 12V B-Series engines requiring a .010" oversize head gasket
- Ideal for engines that have been resurfaced or decked
Note: Always verify required gasket thickness after machining. Incorrect gasket thickness can result in improper compression ratio or valve-to-piston clearance.
Cross-Reference (Cummins-Only)
Related Cummins 12-Valve engine sealing components:
• Cummins 3900267 Tappet Cover Bolt Grommet Seal
• Cummins 3904408 Valve Stem Guide – 60.50mm
• Cummins 3904409 Valve Stem Guide – 51.75mm
FAQ
Why is this head gasket .010” oversize?
The .010” oversize gasket compensates for machined cylinder head or block surfaces to maintain proper sealing and compression height.
Does this kit include the intake and exhaust manifold gaskets?
Yes. This is an upper engine kit, which includes intake, exhaust, valve cover, and other upper-end sealing components.
Can this be used on an unmachined engine?
It is not recommended. OEM thickness must match original deck height. Use standard thickness if the block/head has not been resurfaced.
Is this an OEM Cummins kit or aftermarket?
This is a 100% genuine Cummins kit, not an aftermarket reproduction.
Is this kit correct for 24-Valve (1998.5+) engines?
No. This kit is for 1989–1998 12-Valve 6BT engines only. 24-Valve ISB engines use different gaskets.
Specifications for cummins 4089650
| Specification | Value |
|---|---|
| Brand | Cummins Genuine Parts |
| Part Number | 4089650 |
| Component Type | Upper Engine Gasket Kit – .010 Oversize |
| UPC | Not Published |
| GTIN | Not Published |
| Cross Reference | OEM replacement for 5.9L 12V head gasket sets; verify by ESN for correct oversize |
| E-Codes | N/A |
| Shipping Weight | 5.0 lbs (varies by packaging) |
| Package Dimensions | 26 x 12 x 4 in (approx.) |
| Prop 65 Warning | Not Applicable |
