Product Description
Interstate-McBee M-3946275 Exhaust Manifold Gasket — 1998.5–2007 5.9L Cummins (24-Valve)
Aftermarket replacement exhaust manifold gasket for the 1998.5–2007 Dodge Ram 2500/3500 with the 5.9L Cummins 24-valve (ISB). Built to OE form, fit, and function to seal the manifold to the cylinder head. Sold individually.
- Direct fit: Matches Cummins reference 3946275 for 24-valve ISB applications.
- Leak prevention: Proper sealing between the exhaust manifold and cylinder head.
- Service ready: Ideal for manifold swaps, stud/nut service, or leak repairs.
- Value: Interstate-McBee quality at an excellent price point.
Specifications
| Brand | Interstate-McBee |
| Part Number | M-3946275 |
| OEM Reference | Cummins 3946275 |
| Sold As | Each (1 gasket) |
| Qty Required | 6 gaskets (one per exhaust port on 5.9L 24-valve) |
| Position | Exhaust manifold-to-cylinder head |
What’s Included
- (1) Exhaust manifold gasket, P/N M-3946275
Vehicle Fitment
Always verify by engine serial number (ESN) when possible.
- Dodge Ram 2500/3500 — 5.9L Cummins (24-valve ISB)
- Model Years: 1998.5–2007
Recommended/Related Parts
- Exhaust manifold hardware kit (studs and nuts)
- Turbocharger outlet gasket / downpipe V-band clamp (as applicable)
- Exhaust manifold (stock replacement or performance)
- Penetrating oil and anti-seize compound (for hardware service)
Install Notes
- Clean both sealing surfaces thoroughly; remove old gasket material and carbon.
- Install gaskets dry unless your service manual specifies otherwise.
- Follow the correct torque spec and sequence for the manifold fasteners.
- After a full heat cycle, recheck torque where recommended by the service manual.
Why Buy From CPP Diesel
- ESN-verified fitment support from diesel specialists
- Fast shipping, easy returns, competitive pricing
- Extensive inventory for Cummins ISB service
FAQ
How many gaskets do I need?
The 5.9L 24-valve uses six individual gaskets (one per exhaust port). This listing is for a single gasket.
Does this fit 12-valve engines (1989–1998)?
No. This part number is for the 24-valve ISB (1998.5–2007). See 12-valve listings for earlier engines.
Should I replace studs and nuts?
Recommended if hardware is corroded, stretched, or if you’re installing a new manifold. Proper torque is critical for sealing.
