Product Description
Interstate-McBee M-3904409 Exhaust Valve Guide – 51.75 mm – 1989–1998 5.9L Cummins 12-Valve
OE-style exhaust valve guide for the 5.9L Cummins 12-valve (6BT) used in 1989–1998 Dodge Ram 2500/3500. Designed to restore correct stem support and heat transfer for long service life. Sold individually.
- Direct fit: Built to OE form and geometry for consistent press fit and alignment.
- Correct length: 51.75 mm overall for the specified 12-valve 6BT applications.
- Service ready: Intended for standard cylinder-head reconditioning procedures (press-in, then size/hone/ream to spec).
- Value: Interstate-McBee quality at an aftermarket price.
Specifications
| Brand | Interstate-McBee |
| Part Number | M-3904409 |
| Application | Exhaust valve guide |
| Overall Length | 51.75 mm |
| Sold As | Each (1 guide) |
| Qty Required (12-valve) | 6 (exhaust valves only) |
| Position | Cylinder head → exhaust valve guide |
| OEM Reference | Cummins 3904409 (verify by ESN) |
What’s Included
- (1) Exhaust valve guide, P/N M-3904409
Vehicle Fitment
Always verify by engine serial number (ESN) when possible.
- Dodge Ram 2500/3500 with 5.9L Cummins 12-valve (6BT)
- Model Years: 1989–1998
- Other B-Series applications where Cummins 3904409 is specified (confirm by ESN).
Install Notes
- Professional machine-shop procedures recommended: remove old guide, clean bore, press in new guide, then ream/hone to final stem clearance per the service manual.
- Check installed height and concentricity; verify stem-to-guide clearance with a bore gauge.
- Service one cylinder at a time; follow all Cummins torque and temperature guidelines.
Recommended/Related Parts
- Intake valve guides (for complete set)
- Exhaust valves and valve stem seals
- Valve keepers/locks and retainers
- Head gasket and related upper engine gaskets
FAQ
How many guides do I need?
For exhaust only, you’ll need 6 guides on a 12-valve 5.9L (one per exhaust valve). If you’re doing both intake and exhaust, that’s 12 total guides.
Do these require machining after install?
Yes. After pressing in the guide, the bore is typically finish-reamed or honed to achieve the correct stem clearance and alignment.
Will this fit 24-valve (1998.5–2002) engines?
No. This listing is for the 12-valve 6BT only. Verify by ESN for borderline build dates.
Why Buy From CPP Diesel
- ESN-verified fitment support from diesel specialists
- Fast shipping and easy returns
- Deep inventory of B-Series valvetrain parts
