Bartman was the only one who mentioned his temperature being 180 degree or higher. I have the 95 TBI and not the LT-1 but the book says 142 for the TBI and 142/160 for the LT-1. If it were me, I would replace the thermostats or at least take them out and see if the problem goes away with the engine running cold. It is possible that 180+ degrees is just on the boarder line of being too hot.
Several of us with the 95 TBI Maristars have the 142 thermostat and the engine acts up if we try to run the 160 thermostat. The engine will run at 160 degrees but doesn't want restart after it has been shut off.
“You realize your odds of winning the lottery are the same as being mauled by a polar bear and a regular bear in the same day”….E-Trade Baby.