My bad, I should've mentioned it being an '85 right off the bat. And I think I might have seen "Sanden" on the plaque/stick before it all disappeared.
But, either way, Iowa's suggestions worked! I tightened the A/C belt which seems to be doing the trick for the moment.
I was going to take it to show it off at a family dinner, but it started overheating, I think. It's odd; the temp gauge seemed all right before today, but when I started it this afternoon, the needle was already halfway up. And continued to climb. I let it run for a minute or two with the temp gauge almost at its peak, but nothing under the engine seemed like it had even warmed up. Definitely wasn't overheated, but it scared me enough to not take it out for a spin.
I appreciate all of the help.