Product Description
Interstate-McBee M-3963379 Rocker Lever (Rocker Box) Cover Gasket – 03–24 5.9L/6.7L Cummins
High-quality aftermarket rocker lever (rocker box) cover gasket engineered by Interstate-McBee as an OEM-style replacement for 2003–2007 5.9L ISB 24-valve and 2007.5–2024 6.7L ISB Cummins engines. Designed to provide a reliable seal between the rocker housing and the cylinder head to help prevent oil seepage and maintain factory performance.
- Direct-fit replacement: Matches Cummins 3963379 specifications for form, fit, and function.
- Consistent sealing: Quality materials and precise cutting for long-term leak prevention.
- Aftermarket value: Interstate-McBee performance and reliability at a cost-effective price.
- Easy install: Drop-in gasket—no modifications required when used on stock housings.
Specifications
| Interstate-McBee Part | M-3963379 |
|---|---|
| OEM Cross-Reference | Cummins 3963379 |
| Application | Rocker lever / rocker housing (rocker box) cover gasket |
| Position | Between rocker housing and cylinder head |
| Category | Gaskets & Seals |
Vehicle Fitment
Always verify by engine serial number (ESN) for exact compatibility.
- Ram 2500/3500 – 5.9L Cummins (ISB 24V): 2003–2007
- Ram 2500/3500/4500/5500 – 6.7L Cummins (ISB): 2007.5–2024
- Additional: ISB/QSB industrial variants where Cummins 3963379 is specified
Installation Notes
- Clean mating surfaces thoroughly; remove all old gasket material and residue.
- Inspect the rocker housing for warpage or damage before reassembly.
- Install gasket dry unless your Cummins service manual calls for sealant in specific areas.
- Follow factory torque sequence/spec for rocker housing fasteners.
Warranty
New Interstate-McBee engine parts are backed by a 24-month warranty from the date of installation (no mileage/hour limit). See manufacturer policy for details.
Why Buy From CPP Diesel
- ESN-verified fitment support from real diesel techs
- Fast shipping and hassle-free returns
- Huge selection of B-Series/ISB gaskets to complete your service
FAQ
Is this the same as a valve cover gasket?This is the rocker lever (rocker box) cover gasket that seals the rocker housing to the cylinder head—sometimes referred to as the “lower valve cover” gasket. It is not the upper cosmetic cover seal.
Will it fit both 5.9L and 6.7L Cummins?
Yes. Listed for 2003–2007 5.9L ISB and 2007.5–2024 6.7L ISB applications where Cummins 3963379 is specified. Verify by ESN for late-model or industrial variants.
Do I need to replace bolts or grommets?
Reuse of hardware depends on condition and service manual guidance. Replace any stretched, damaged, or corroded fasteners and grommets.
Can I reuse the old gasket?
Reuse is not recommended. A fresh gasket ensures proper sealing and helps prevent oil seepage.
Product Videos
Custom Field
YEAR 2003-2018
MAKE DODGE
ENGINE 5.9L,6.7L
