i'm running (about 250 miles so far) on 5 cylinders... its rough, shaking and general rough running
easiest way to find a dead cylinder, starting with a cold engine, fire it up and let it run for 2-3 minutes, take a squirt bottle full of water (or spit on it) and spray each of the exhaust runners, they will steam off really quick, one will be noticeably slower to steam off.
takes a lot less time and less risk of shocking the crap out of yourself than the spark plug pulling method.
plus as i noticed, the truck runs about the same with 4 or 5 cylinders, once you're down to 5 it is running so rough, its hard to tell which cylinder makes it worse or better.