Thanks for the feedback, guys. I'll post with what I find once inside of the belt cover, when I can visually check the tensioner.

Right now the real challenge is the pulley bolt. I've been hitting it hard for minutes on end with a 250 ft-lb impact gun and the bolt is just laughing evilly at the gun. Even after a really good penetrating oil overnight, this wrench is simply undertorqued for the bolt job.

Time to go find a shop with a BIG compressor and a gun rated to 400. If that won't do it, well, time to sell the car quickly :-)