Interstate-McBee M-4089977 Piston Kit – .040" (1.00mm) Oversize for 03–04 5.9L Cummins 305HP

OEM-style .040" (1.00mm) oversize piston kit engineered for the 2003–2004 5.9L Cummins ISB (305HP). This direct-fit aftermarket kit includes the piston, hardened wrist pin, retainers, and ring set—ideal for overbore rebuilds requiring precise compression and durability.

• Application specific: For 2003–2004 5.9L Cummins 305HP engines.
• Oversize spec: .040" overbore (1.00mm) for properly machined cylinders.
• Complete single-cylinder kit: Includes piston, hardened pin, retainers, and rings.
• Direct-fit replacement: Aftermarket value with OEM-style performance.

Specifications

Vehicle Fitment

Verify by VIN/engine tag before ordering—see notes below.

• Dodge Ram 2500/3500 – 5.9L Cummins ISB (2003–2004, 305HP)

Important notes:

• 2003 model year: only High Output (HO) trucks are 305HP.
• Early 2004 model year: Federal emissions trucks are 305HP; California emissions trucks are not compatible with this piston.
• VIN check: 8th digit C = HO (305HP), 6 = SO. Engine tag power rating of 305HP confirms compatibility.

Install Tips

• Confirm machine shop overbore to 1.00mm (.040") and measure piston-to-wall clearance per Cummins specs.
• Check ring end gaps in the finished bore; orient ring gaps per service manual.
• These kits are sold individually (one cylinder). An inline-6 requires six kits for a full set.

Warranty

Interstate-McBee new engine components carry manufacturer warranty coverage. Contact us with your ESN for current terms applicable to piston kits.

Why Buy From CPP Diesel

• ESN/VIN-verified fitment support for 5.9L ISB nuances (HO vs SO; Federal vs California).
• Fast shipping, responsive support, and diesel-focused product curation.
• Trusted aftermarket brands like Interstate-McBee for reliable rebuilds.

FAQ