Product Description
Interstate-McBee M-4089950 Piston Kit STD for 2003-2004 Cummins 5.9L 24-Valve 305HP
The Interstate-McBee M-4089950 Standard Bore Piston Kit is a high-quality aftermarket replacement designed for 2003-2004 Dodge Ram 2500 and 3500 trucks equipped with the 5.9L 24-Valve Common Rail Cummins diesel engine rated at 305 horsepower. Engineered to deliver OE-equivalent fit, function, and durability, this piston kit is ideal for engine rebuilds, overhauls, and service repairs requiring dependable long-term performance.
Manufactured to strict quality standards, the M-4089950 piston kit includes a standard-size piston, piston rings, wrist pin, and pin retainers, providing everything needed for a complete piston assembly. Designed to match the original piston bowl and combustion characteristics, this kit helps maintain proper compression, fuel efficiency, and engine performance when rebuilding your Cummins engine.
Whether you're performing a stock rebuild or refreshing a high-mileage 5.9L Cummins, Interstate-McBee components are trusted throughout the diesel industry for their reliability, precision manufacturing, and proven performance.
Features
- Quality aftermarket replacement piston kit
- Designed for 2003-2004 5.9L Cummins Common Rail engines
- Standard bore (STD) piston assembly
- Matches OE piston dimensions and bowl design
- Includes piston, rings, wrist pin, and retainers
- Ideal for engine rebuilds and overhauls
- Engineered for OE-equivalent fit and function
- Supports proper compression and combustion efficiency
- Trusted Interstate-McBee quality and durability
- Sold individually; six kits required per engine
Fitment
- 2003 Dodge Ram 2500 5.9L Cummins Common Rail 305HP
- 2003 Dodge Ram 3500 5.9L Cummins Common Rail 305HP
- 2004 Dodge Ram 2500 5.9L Cummins Common Rail 305HP
- 2004 Dodge Ram 3500 5.9L Cummins Common Rail 305HP
- Other Cummins ISB applications utilizing OE piston reference 4089950 (Verify ESN/CPL)
Note: Always verify engine serial number (ESN) and CPL before ordering. This is a standard bore piston kit and should only be used in cylinders that remain within factory specifications or after proper machine work and honing.
What's Included
- (1) Standard Bore Piston
- (1) Standard Bore Ring Set
- (1) Wrist Pin
- (2) Pin Retainers / Locks
Specifications
- Manufacturer: Interstate-McBee
- Part Number: M-4089950
- Product Type: Piston Kit
- Bore Size: Standard (STD)
- Engine Compatibility: 5.9L 24-Valve Cummins Common Rail
- Horsepower Rating: 305 HP Applications
- Engine Family: Cummins ISB
- Piston Style: OE-Equivalent Bowl Design
- Ring Set Included: Yes
- Wrist Pin Included: Yes
- Pin Retainers Included: Yes
- Installation Location: Individual Cylinder
- Quantity Required Per Engine: Six Kits
- Condition: New Aftermarket Replacement
Cross Reference Numbers
M-4089950, M4089950, 4089950, Cummins 4089950, Cummins 5.9L 305HP Piston Kit, ISB Common Rail Piston Kit
FAQ
How many piston kits are required for a complete engine rebuild?
This piston kit is sold individually. Six piston kits are required to rebuild all six cylinders in a 5.9L Cummins engine.
Does the kit include rings and a wrist pin?
Yes. Each Interstate-McBee M-4089950 kit includes the piston, piston ring set, wrist pin, and pin retainers.
Will this fit all 2003-2004 Cummins engines?
Not necessarily. Cummins used multiple CPLs and piston configurations. Always verify compatibility using the engine serial number (ESN) and CPL before purchasing.
Can I use this standard bore piston in a worn cylinder?
No. If cylinder measurements exceed factory specifications, the block should be machined and the appropriate oversize piston selected.
Is this a genuine Cummins piston kit?
No. This is a high-quality aftermarket replacement piston kit manufactured by Interstate-McBee and designed to meet OE performance requirements.
What engine applications is this piston designed for?
This piston kit is commonly used in 2003-2004 Dodge Ram 2500 and 3500 trucks equipped with the 5.9L Common Rail Cummins engine rated at 305 horsepower.
