Your truck has coil packs. Easily bought at any parts store. Use a code scanner (if you have a CEL) to determine which cylinder is misfiring. I think its a 10mm bolt that holds them down, unplug the electrical connection and pull it free from the plug. Dont forget to add dielectric grease with the new coil pack.
My 2000 4.6L gave me troubles with these things all the time.