If you are concerned about one specific cylinder, then testing everything by pulling the plug, attach the plug wire, then grounding the threads, then turning the truck over and seeing if you getting spark across the gap may help. If you just want to see if you are getting spark at all, take the coil wire off the cap, poke a screw driver in the wire and get the exposed metal of the driver *near* the manifold, (dont touch it to metal or the energy wont have a gap to jump, thus you wont see a spark). You should see sparkage when you crank. What is the prob, specifically? What happened and when?
How are your fuses?
Daron