Torque Converter Stuck

Paint a thick coat of anti seize compound on the converter hub where it goes into the crank when you put it back together and it won't do that again.
I don't really think it was seized. There was a bunch of grease on the back of it, and I believe it was creating a vacuum that was holding it in place. I'll be sure to get the paint off the hub when I put the 383 in this weekend though, and give it a little anti seize as well.