It's fixed! 4onthefloor and Vwnate were on the money. After tearing the carb down again, I noticed the power piston hanging up. The stem was slightly bent, which caused it to bind where it meets up with the ball in the power valve. After straightening the stem, I polished the power piston body with some emery cloth. My 57 stepside has come alive again. Thanks to all for the ideas.
