Product Description
Interstate-McBee M-3901221 Short Rocker Mounting Stud – 1989–1998 5.9L Cummins 12-Valve
Short rocker mounting stud for the 5.9L Cummins 12-valve (6BT) valvetrain used in 1989–1998 Dodge Ram 2500/3500. Built to OE form, fit, and function for reliable rocker shaft service. Sold individually.
- Direct fit: Replaces the factory short rocker stud in the OE location.
- OE-equivalent quality: Interstate-McBee aftermarket replacement engineered for durability.
- Service friendly: Ideal for rocker shaft rebuilds and top-end refreshes.
Specifications
| Brand | Interstate-McBee |
| Part Number | M-3901221 |
| OEM Reference | Cummins 3901221 |
| Component | Short rocker mounting stud (valvetrain) |
| Sold As | Each (1 stud) |
What’s Included
- (1) Short rocker mounting stud, P/N M-3901221
Vehicle/Engine Fitment
Always verify by engine serial number (ESN) when possible.
- Dodge Ram 2500/3500 5.9L Cummins (12-valve 6BT)
- Model Years: 1989–1998
- Other B-Series applications where Cummins 3901221 is specified (confirm by ESN).
Install Notes
- Clean threads and inspect rocker pedestals and shaft for wear before installation.
- Use proper torque per the Cummins service manual; apply thread lubricant or sealant only if specified.
- Service one assembly at a time to maintain rocker/bridge orientation.
Recommended/Related Parts
- Rocker shaft assembly and pedestals (12-valve)
- Rocker arm retaining nuts / hardware kit
- Push rods (12-valve)
- Valve cover gasket set
FAQ
Is this the short or long stud?
This listing is for the short rocker mounting stud (M-3901221). If you need the long stud, search by the long-stud part number or contact support with your ESN.
How many do I need?
Stud count can vary by assembly and service procedure. Verify quantity for your specific engine build in the Cummins manual or by ESN. Parts are sold individually.
