Product Description
Interstate-McBee M-3800781 Piston Kit (STD) — 1998.5–2002 5.9L Cummins 24-Valve ISB
Quality aftermarket piston kit engineered to OE specifications for the 1998.5–2002 Dodge Ram 2500/3500 with the 5.9L Cummins 24-valve ISB. Standard bore size (STD). Sold individually (per cylinder).
- OE-style construction: Designed for factory performance and durability.
- Matched components: Piston, ring set, wrist pin, and pin retainers included for each cylinder.
- Direct fit: Intended for engines calling for Cummins ref. 3800781 (verify by ESN).
- Service-ready: Ideal for stock rebuilds and refreshes.
Specifications
| Brand | Interstate-McBee |
| Part Number | M-3800781 |
| OEM Reference | Cummins 3800781 |
| Size | Standard (STD) |
| Engine | 5.9L Cummins ISB, 24-Valve |
| Sold As | Each (1 piston kit per cylinder) |
| Qty Required for Full Engine | 6 kits (one per cylinder) |
| Contents | Piston, ring set, wrist pin, pin retainers |
What’s Included
- (1) Piston — STD
- (1) Piston ring set (matched to piston)
- (1) Wrist pin
- (2) Pin retainers/locks
Vehicle Fitment
Always verify fitment by engine serial number (ESN) and block casting.
- Dodge Ram 2500 / 3500 — 5.9L Cummins ISB, 24-Valve
- Model Years: 1998.5–2002
- Other B-Series applications where Cummins 3800781 is specified (confirm by ESN).
Recommended/Related Parts
- Additional piston kits (order 6 total for full rebuild)
- Piston ring compressor
- Rod and main bearings
- Full gasket set / head gasket
- Head bolts or studs
- Oil pump and timing components as needed
Install Notes
- Measure cylinder bores and confirm standard size before ordering/installation; hone as required.
- Check ring end gap in-cylinder and adjust per service manual.
- Observe piston orientation marks and connecting rod offset.
- Verify piston protrusion and clearances; follow the Cummins service manual for torque and procedures.
- Lubricate rings, pin, and skirts appropriately during assembly.
Why Buy From CPP Diesel
- ESN-verified fitment support from diesel specialists
- Fast shipping and easy returns
- Extensive inventory of complementary ISB rebuild parts
FAQ
Is this kit for one cylinder or a full set?
This listing is for one piston kit (per cylinder). A full engine requires six kits.
What size is it?
Standard (STD) bore. If your block requires oversize pistons, select the correct oversize part instead.
Will this fit my 1998 truck?
It fits 1998.5 (mid-year change) through 2002 24-valve ISB engines. For early-1998 12-valve trucks, this is not correct.
Do the rings come pre-gapped?
Rings are supplied to suit the piston; always check and set end gap during installation.
