Update on the 3800 Fiero. Today I removed the AC compressor. A MUCH easier job than removing one from a stock V6 Fiero. It was definitely the reason for the noise. It not only makes a racket when you spin the pulley, but it wobbles. The bearings in it are toast.
The part number on it is the correct part number for a 96 Buick compressor, so I bought a new one off Ebay. Only $35 bucks more than a delete pulley would have cost, so why not?