Let me throw a little help your way. Instead of jacking the truck to take the caged pulley off, remove the shroud and fan. Then you can do the job from above. First you must remove the plastic cover on top of the radiator. Then put a large adjustable wrench on the nut on the fan, and whack it with a large mallet toward the passenger side. It will come loose, might take a bunch of whacks but it will come loose. Then there are just two bolts that hold the fan shroud on. Remove those, then take out the fan and shroud at the same time. Now you have all the room in the world to work on the lower pulley from above. Since the lower pulley is reversed threaded ,when working on it from above, you will loosen it towards the driver's side when working on it from above.
A friend of mine and me did mine from the bottom. But since, I've had to take off t he bolt-on pulley twice. I always go ahead and remove the fan and shroud to do this. Plus, when working on it from above, you can use a longer tool to remove that stupid stock pulley. A long breaker bar, with maybe a piece of pipe over it to extend it's length. If you do that, it should be a snap to get the pulley off.