Product Description
Cummins 3920780 — Hexagon Flange Head Cap Screw (Cylinder Head Bolt)
MPN: 3920780 | Also Known As: cylinder head bolt, hex flange head cap screw | Related: 3920779 (short bolt)
Why This Part
- ✓ OE fastener for 5.9L 12-valve B-series cylinder head mounting.
- ✓ Direct-fit hardware for 1989–1998 Ram 5.9L 12V (verify by VIN/ESN).
- ✓ Correct flange head design for proper clamping and alignment.
- ✓ Sold individually so you can replace by position or refresh a full set.
Quick Specs
| Type | Hexagon Flange Head Cap Screw (Cylinder Head Cap Screw) |
|---|---|
| OE Part # | 3920780 |
| Application | 5.9L 12-valve B-series head mounting; pairs with 3920779 in mixed-length sets |
| Qty Required | Order by position per service manual (mixed long/short). Sold individually. |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1989–1998 | 5.9L 12-Valve B-Series (VE ’89–’93, P7100 ’94–’98) | Dodge Ram 2500/3500 |
Industrial/Off-Highway: Common across 4B/6B/ISB and QSB families—always confirm by ESN.
Often Paired With
- Head gasket set: 5.9L 12-valve (choose by year/ESN)
- Short head bolt: Cummins 3920779 (where specified)
- Upgrade option: ARP head stud kit (when increasing cylinder pressure)
What’s In The Box
- (1) Genuine Cummins Hex Flange Head Cap Screw (3920780)
Install Tips
- Clean threads and chase block holes; light oil under head and on threads per Cummins procedure.
- Follow the factory torque sequence and spec; do not substitute lengths/positions.
- Recheck torque after initial heat cycle if specified by the service manual.
FAQ
WILL THIS FIT MY 1989–1998 5.9L 12-VALVE RAM?Yes—3920780 is used on 12-valve 5.9L B-series head fastener locations. Verify by VIN/ESN and position before ordering.
IS 3920780 THE LONG OR SHORT CYLINDER HEAD BOLT?3920780 is commonly used as the long cap screw in mixed-length sets; 3920779 is typically the short. Always confirm positions in the factory manual.
HOW MANY DO I NEED?The 5.9L 12V uses a mix of long and short bolts. Check the service manual for counts and positions; this listing is sold individually.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins 3920780 with the correct flange-head design and hardness.
CAN I MIX 3920780 WITH 3920779 BOLTS?Yes—if installed in their specified positions. Do not interchange lengths; replacing as a full matched set is best practice during rebuilds.
