I just ordered the Milodon #16250 water pump and the Milodon high flow 180 thermostat. I just replaced the thermostat last week with a standard NAPA 180 but I read that a HF pump needs the HF thermostat. I needed a few bucks to get the free shipping, so I ordered the Milodon 180 thermostat too.

I am assuming the pump went bad or that my belt tension was too tight. I put on a Powermaster (120a) alternator which took a little more belt tension to keep it quiet. I wonder if either was the actual issue.

Thanks to everyone!