Product Description
Interstate-McBee M-3963379 Rocker Lever Cover Gasket — 2003–2024 5.9L/6.7L Cummins (Aftermarket Replacement)
Direct-replacement rocker lever cover (valve cover) gasket for the 2003–2024 Cummins ISB/6.7L platforms, including late 5.9L common-rail and 6.7L applications. Built to OE form, fit, and function for a reliable seal. Sold individually.
- OE-style fit: Matches Cummins reference 3963379 for correct sealing and bolt pattern.
- Durable materials: Designed to withstand heat, oil, and vibration in the upper valvetrain area.
- Service friendly: Ideal for valve set / valve cover service, leak repair, or top-end refresh.
- Value: Interstate-McBee quality at an affordable price point.
Specifications
| Brand | Interstate-McBee |
| Part Number | M-3963379 |
| OEM Reference | Cummins 3963379 |
| Application | Rocker lever cover (valve cover) gasket |
| Sold As | Each (1 gasket) |
| Typical Location | Upper engine — under the valve cover |
What’s Included
- (1) Rocker lever cover gasket, P/N M-3963379
Vehicle/Engine Fitment
Always verify by engine serial number (ESN) when possible.
- Cummins ISB 5.9L (common-rail) — 2003–2007
- Cummins 6.7L — 2007.5–2024
- Additional ISB/6.7L applications where Cummins 3963379 is specified (confirm by ESN).
Recommended/Related Parts
- Valve cover bolt grommets / isolators (replace if brittle or oil-soaked)
- Valve cover (rocker lever cover) hardware set as needed
- Upper engine gasket set (for comprehensive top-end service)
Install Notes
- Clean the sealing surfaces thoroughly; remove old gasket material and oil residue.
- Do not use sealant unless specified by your service manual.
- Install gasket dry and torque valve cover fasteners in an even, criss-cross pattern to spec.
- After initial heat cycle, inspect for leaks and recheck torque if the manual calls for it.
Why Buy From CPP Diesel
- ESN-verified fitment help from diesel specialists
- Fast shipping and easy returns
- Deep inventory of complementary ISB/6.7L service parts
FAQ
Is this the correct gasket for my 2003–2007 5.9L Cummins?
Yes, this listing covers the common-rail 5.9L (2003–2007) when Cummins 3963379 is the specified reference. Verify by ESN for best results.
Does this fit 6.7L Cummins?
Yes, it covers 6.7L ISB applications (2007.5–2024) where 3963379 is specified. Confirm by ESN or parts catalog.
Do I need new bolt grommets?
Recommended. Aged grommets can cause uneven clamp load and leaks. Replace if hardened, swollen, or cracked.
