Overheating problem/burning smell solved: I replaced the GNB? water pump (been on for five years) with a volvo unit. I don’t think the GNB piece was totally at fault, but due to the powdery gasket material around the shaft seal, was definitely due for a replacement. Just as aside: the impeller design on the Volvo piece is totally superior to the GNB piece (regarding how much water it looks like it can push)- so much so that I’ll only use Volvo water pumps from now on. I also replaced the original thermostat (161k) with a Napa piece. Did a side by side test on both thermostats in boiling water gauged with a candy thermometer. They both seemed consistent - on opening and closing. Although the orignal thermostat seemed a bit quicker to open and close. After replacing the thermostat AND the cooling fan sensor (plugs into the top of the radiator), the cooling is all back in order. I believe the thermostat was sticking - and this was the primary cause.

The burning smell? Plastic walmart bag caught on the cat. converter. Can you believe that?

ChrisH - thanks again for your informative post. I truly appreciate you taking the time to do it. BTW - I’m originally from DesPlaines. Don’t know if that means anything...other than I still like old style and the bears. Thanks man!