Product Description
The CUMMINS 4089950 OEM PISTON KIT (STANDARD) is designed for 2003–2004 ISB 5.9L Cummins 305HP common rail diesel engines. This genuine Cummins piston kit is engineered to restore factory compression, combustion efficiency, and long-term engine durability while maintaining OEM specifications and fitment.
Use this piston kit during engine rebuilds, overhauls, cylinder repairs, or when replacing damaged pistons. Always verify engine serial number, piston size, and application before ordering.
FEATURES
- Genuine Cummins OEM piston kit
- Standard bore size piston assembly
- Designed for 2003–2004 ISB 5.9L 305HP Cummins engines
- Restores factory compression and combustion performance
- Engineered to Cummins OEM specifications
- Ideal for engine rebuild and overhaul applications
FITMENT
- 2003–2004 Dodge Ram 2500 5.9L Cummins ISB 305HP
- 2003–2004 Dodge Ram 3500 5.9L Cummins ISB 305HP
- Select Cummins ISB 5.9L industrial applications utilizing the 305HP common rail engine platform
WHAT'S INCLUDED
- 1 Cummins 4089950 Standard Piston Kit
- Piston
- Piston Pin
- Retainers and associated components as supplied by Cummins
CROSS-REFERENCE AND RELATED PRODUCTS
- Cummins 4089950
- Cummins Standard Bore Engine Components
- Cummins Connecting Rod Components
- Cummins Piston Ring Sets
- Cummins Cylinder Liner Service Components
SPECIFICATIONS
- Manufacturer: Cummins
- Part Number: 4089950
- Part Type: Standard Piston Kit
- Engine Compatibility: ISB 5.9L Cummins 305HP Common Rail
- Fitment Years: 2003–2004
- Vehicle Application: Dodge Ram 2500 / 3500
- Bore Size: Standard
- Condition: New OEM Cummins
- Installation Type: Engine Rebuild / Overhaul Replacement
FAQ
Will this piston kit fit my Cummins engine?
This piston kit is designed for specific 2003–2004 ISB 5.9L Cummins 305HP applications. Always verify fitment using your engine serial number before ordering.
Is this a standard bore piston?
Yes. Cummins 4089950 is a standard bore piston kit intended for engines that do not require an oversize piston during rebuilding.
What is included in the kit?
The kit includes the piston and related installation components supplied by Cummins for the application.
Can this be used during a complete engine rebuild?
Yes. This piston kit is commonly used during complete engine overhauls, in-frame repairs, and performance restoration projects.
Should piston rings be replaced at the same time?
Yes. New piston rings, liners, bearings, and related wear components are typically replaced during piston installation.
Do I need any related parts?
Inspect cylinder liners, piston rings, connecting rods, rod bearings, wrist pins, and gasket components during engine service and replace worn parts as necessary.
