EJO, thanks for the help. My ez-out is the reverse threaded kind. It would seem to me, though, that you'd create the same expansive pressure by driving a square one in far enough to get a good bite as you do by twisting in the tapered threads, so I haven't tried anything square yet. I'm afraid I'll break off a file handle. The only heat source I have is a propane torch, which goes out after a few seconds of being held upside down (which is the only way to get the tip down in the hole) and is therefore pretty useless. I do have an electric soldering iron, but doubt that would get things hot enough. If I heat it up by running the motor, is there anything to watch for/be careful about while running on three cyl with #2 open to the elements? I would assume it'd have to run for a good 10-15 min to heat up this area since only the adjacent cylinders are firing, no?

I can't shake the feeling that this is headed towards me drilling the #%*% thing out...how do I tell whether I'm at the top of a compression stroke or exhaust stroke? Do you have to take off the valve cover and look, or is there a trick? Thanks everyone, I'm starting to get in over my head here and really appreciate the help.