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

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

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