UPDATE:

Well, I replaced the fan clutch, and installed the thermostat. I took her out for a 45min ride at highway speeds (34 to 70mph) sustained for about 30min. The temp gauge did not move from slightly above normal. Granted that it was 78F when I tried at 5am, but apparently it's not overheating. Since it's summer, I'll try doing a longer run at 100+F heat and post another update.