Product Description
CUMMINS 4376348 OEM ENGINE PISTON KIT (.020) – ISB 6.7L (2007.5–2018)
The genuine CUMMINS 4376348 OEM engine piston kit (.020 oversize) is the factory-spec piston used when rebuilding or machining a 2007.5–2018 6.7L ISB Cummins engine. Oversize pistons are required when cylinder bores are worn, out of round, scored, or being resurfaced during an engine overhaul. This .020-inch oversize piston restores correct compression, ring seal, and combustion efficiency—critical to maintaining the power and longevity of your 6.7L Cummins.
Unlike aftermarket pistons, this OEM Cummins assembly uses the correct alloy, thermal expansion properties, skirt coating, and ring land geometry to maintain reliability under towing, commercial, and high-load conditions. Each kit includes the piston and matching rings engineered specifically for 6.7L ISB applications.
Key Features
- Genuine Cummins OEM piston kit – engineered for ISB 6.7L engines.
- .020" oversize piston for machined cylinder bores.
- Correct metallurgy and skirt coating for thermal stability.
- Precision-fit ring pack designed for OEM crosshatch patterns.
- Restores compression and reduces blow-by on rebuilt engines.
Fitment Details
- Engine: Cummins ISB 6.7L
- Years: 2007.5–2018
- Piston Size: .020" Oversize
- Applications: Ram 2500, Ram 3500, cab & chassis, ISB commercial variants
- Notes: Only for cylinders bored .020" over. Always confirm size by machine shop measurement.
Cross-Reference & Companion Cummins Parts
CPP Diesel stocks multiple Cummins OEM components commonly used during a piston or engine rebuild:
- CUMMINS 4891175 MAIN BEARING KIT – 5.9L / 6.7L
- CUMMINS 4955851 ROD BEARING KIT – 5.9L / 6.7L
- CUMMINS 4981790 VALVE STEM SEAL – 5.9L & 6.7L
- CUMMINS 5264569 HEAD GASKET – 6.7L
- VIEW ALL CUMMINS OEM ENGINE COMPONENTS
Common cross-reference numbers: 4376348, 4376348NX (reman), 4376349 (size variants).
Installation Notes
- Machine shop measurement REQUIRED before selecting .020" oversize pistons.
- Always replace pistons in sets for uniform compression.
- Verify ring end gap according to Cummins specifications.
- Use proper lubrication during assembly.
- Follow torque sequence and bearing clearances during reassembly.
Specifications for cummins 4376348
| Attribute | Value |
|---|---|
| Brand | Cummins (Genuine OEM) |
| Cummins Part Number | 4376348 |
| Oversize | .020" (0.50mm) |
| Function | Engine piston kit with rings for oversize bore |
| Engine Compatibility | Cummins ISB 6.7L (2007.5–2018) |
| Vehicle Fitment | Ram 2500 / 3500, cab & chassis, ISB industrial platforms |
| UPC | 190910285324 |
| GTIN | 190910285324 |
| Shipping Weight | Approx. 3.2 lbs per piston kit |
| Shipping Method | Standard ground; expedite available |
| E-Codes / Emissions | Non-emissions component — internal engine part |
| Prop 65 Warning | WARNING: May expose you to chemicals known to the State of California to cause cancer and reproductive harm. Visit www.P65Warnings.ca.gov. |
| Country of Origin | As labeled by Cummins (varies by production batch) |
Frequently Asked Questions
WHEN SHOULD I USE A .020 OVERSIZE PISTON?
Use .020 oversize pistons when your machine shop confirms cylinder wear or damage requiring a .020" overbore. Never assume size—always measure.
DO I NEED TO REPLACE ALL SIX PISTONS?
Yes. Oversize pistons must be installed as a matched set to maintain proper compression and cylinder balance across the engine.
ARE RINGS INCLUDED WITH THIS KIT?
Yes. The Cummins 4376348 piston kit includes the matching ring pack engineered specifically for this piston design.
IS THIS A GENUINE OEM CUMMINS PISTON KIT?
Yes — CPP Diesel supplies only authentic Cummins OEM components from the official distribution network.
