After searching these forums, I found an almost the same situation that I have with my Aries K 1989 sedan. The car when first started in the morning, and driving down the road about 10 to 15 minutes, the heat guage goes almost up into the hot zone. It's stops just below that, and then the gauge drops to cool and for the rest of the driving time, never moves off cool zone. The other thread says this is a thermostat problem, and I should replace it. Which one should I get? My local Autozone shows only three brands, Duralast, Failsafe, and valucraft; no mopar. I know I also need the gasket. I was wondering which one to get because each shows a different temperature, 190, 192. 160 and 180. Would appreciate any answer I am given. Thanks in advance.