I would be concerned using an impact wrench. I think your right NeverEnough, you had a strange circumstance. This impact wrench will possibly overtorq the threads and either strip them, break the bolt or put it back on too tight. With the strap wrench, it is a piece of cake. I was the one that mentioned this idea for two reasons. One is the above.

The second was that I wanted to put the bolt back in precisley the same place. If you look closely, the person that assembled the engine and mounted the original pully marked the bolt and assembly with a white paint line. Most of the time you see this is to tell if someone tampered with the original install or if a bolt is coming loose. I wanted those white lines to line up perfectly just as they were from the factory. The only way to do this is to carefully line them up by hand. I had to start the treadding a few times to get it to line up with the proper torq but it did work.

Steve