Product Description
Interstate-McBee M-3901221 Short Rocker Mounting Stud — 89–98 5.9L Cummins 12V
Heavy-duty short rocker mounting fastener (stud/bolt) for the rocker lever pedestal on 1989–1998 Dodge Ram 5.9L Cummins 12-valve engines. Built to OEM-equivalent specs for a precise fit and durable clamping force in the valvetrain. Cross-references Cummins 3901221.
- Direct fit: OEM-style replacement for the short rocker pedestal fastener on 12V 5.9L.
- Durable construction: Quality aftermarket hardware designed for repeated service cycles.
- Consistent clamping: Helps maintain proper rocker pedestal alignment and valve lash stability.
- Cost-effective: Interstate-McBee value versus OEM boxed hardware.
Specifications
| Brand | Interstate-McBee |
|---|---|
| Part Number | M-3901221 |
| OEM Cross-Ref | 3901221 (Cummins) |
| Position | Rocker lever pedestal — short mounting fastener |
| Engine | Cummins 5.9L 12-Valve (6BT) |
| Applications | Dodge Ram 2500/3500 (see fitment below) |
| What’s Included | (1) rocker pedestal short fastener (no nuts/washers included) |
Vehicle Fitment
Always verify by engine serial number (ESN) when possible.
- Dodge Ram 2500/3500 — 5.9L Cummins 12-Valve
- 1989–1993 (VE-pump)
- 1994–1998 (P7100-pump)
- Notes: Also used across many B-Series 4BT/6BT industrial variants; confirm by ESN for non-automotive engines.
Install Notes
- Follow the Cummins service manual for pedestal hardware order, tightening sequence, and torque values.
- Inspect pedestals and rocker arms for wear; replace any damaged components.
- If using cylinder head studs, ensure valve cover clearance; some builds require notched/machined rockers or pedestals.
Why Buy From CPP Diesel
- Application-correct B-Series hardware curated by diesel techs.
- Fast shipping, easy returns, and ESN-verified fitment support.
- Deep catalog for 12V/24V Cummins valvetrain, gaskets, and fasteners.
FAQ
Is this the correct fastener for 12-valve rocker pedestals?Yes. M-3901221 is the short rocker pedestal fastener for 1989–1998 5.9L Cummins 12V applications. Verify by ESN for edge cases or mixed-year engines.
Is it a stud or a bolt?
It’s an OEM-style rocker pedestal mounting fastener that cross-references Cummins 3901221, commonly listed as a hex head cap screw. Naming varies by catalog, but function and fitment are the same.
How many do I need?
Quantity depends on the pedestal hardware layout. Check your service manual or count existing hardware during teardown.
Will this fit 24-valve (1998.5–2002) engines?
No. 24-valve ISB engines use different valvetrain hardware. Use parts cataloged for 1998.5–2002 5.9L ISB.
Any special torque specs?
Always follow Cummins model-specific torque specs and sequences from the factory service manual.
