Product Description
Interstate-McBee M-3920780 Cylinder Head Bolt – 89–98 5.9L Cummins 12-Valve
Premium aftermarket cylinder head bolt engineered to OEM dimensions for 1989–1998 Dodge Ram 2500/3500 5.9L Cummins (12-valve) applications. Built for consistent clamping force and reliable sealing during stock refreshes or full top-end service.
- OEM cross-ref: Direct replacement for Cummins 3920780.
- Correct length & thread: M12 × 1.75 × 120 mm bolt used at factory-specified positions on 5.9L 12V heads.*
- Durable construction: Heat-treated alloy with flange head for even load distribution.
- Aftermarket value: Interstate-McBee quality at a lower cost than OEM.
Specifications
| Brand / Part # | Interstate-McBee M-3920780 |
|---|---|
| OEM Reference | Cummins 3920780 |
| Thread / Length | M12 × 1.75 × 120 mm (flanged hex) |
| Position | Cylinder head fastener (factory “medium-length” locations*) |
| Sold As | Each (order quantity as needed) |
*Many catalogs label the 120 mm bolt as “medium.” Some listings refer to it as “long.” Verify by ESN or position chart.
What’s Included
- (1) Cylinder head bolt, M-3920780
Vehicle Fitment
Always verify by Engine Serial Number (ESN) for exact applications.
- Dodge Ram 2500/3500 5.9L Cummins (12-Valve)
- Model Years: 1989–1998
- Also seen on: Cummins 4B/6B industrial variants (varies by ESN).
Set Composition (Reference)
A complete 5.9L 12V head bolt set typically uses:
- 6 × Short bolts – Cummins 3920779 (≈70 mm)
- 14 × Medium bolts – Cummins 3920780 (≈120 mm) (this part)
- 6 × Long bolts – Cummins 3920781 (≈180 mm)
Install Notes
- Clean threads and block holes; chase if needed. Lightly oil under-head flange and threads if specified by the manual.
- Follow the factory torque/angle sequence for your ESN; replace any stretched or damaged bolts.
- Do not mix reused bolts with new hardware; consider replacing the full set during head gasket service.
Warranty
Interstate-McBee new parts carry manufacturer warranty coverage. Contact us for terms applicable to head fasteners.
Why Buy From CPP Diesel
- ESN-verified fitment support from diesel specialists
- Fast shipping & hassle-free returns
- Curated B-Series inventory for complete top-end service
FAQ
Is M-3920780 the “long” bolt?Most service charts call 3920780 the medium-length (≈120 mm) bolt used in 14 positions on 5.9L 12V heads. Some catalogs label it “long,” so always match by part number and length.
How many of this bolt does my 5.9L 12V require?
Typically 14 pieces of 3920780, plus 6 short (3920779) and 6 long (3920781) to complete a 26-bolt set.
Will this fit 24-valve (1998.5–2002) engines?
No—this listing targets 1989–1998 12-valve applications. 24-valve engines use different head bolts.
Can I mix bolts and studs?
It’s best to use a complete matched set (all bolts or an engineered stud kit) to maintain uniform clamping.
