These will fit the newer style injector for your 2003-2004 5.9L truck. It matches nozzles number 5499. -Great addition to go along with our BAG O PARTS for the 5.9L dodge.-Maximizes your fuel more efficiently, better atomization-Great for the daily driver looking to increase mileage and bottom end performance for towing.-Can be used with stock injection pump, but the bag o parts makes a great addition along with the nozzles.-Extrude Honed Balanced matched for best results-Great performanceNOTICE: Injector Nozzles are sold individually*All Industrial Injection Performance Products Are Not Legal For "On-Road", "Off-Road", or "Dual-Use". These Products May Only Be used In "Closed Circuit Competition Only" Vehicles. Compliance With State And Federal Emission Standards Is The Consumer's Responsibility.