Test drive it again. When temp hits the high mark (into the red ??), park car, open hood, slowly, very slowly, remove cap from expansion tank . You will know by the pressure/ non pressure if it is a faulty / misreading gauge.
My 89 does this every now and then. Usually once in the spring, and again in the fall. My temp stops just short of the red. Doing above check, no excessive pressure. Have to jump those connections to get an accurate gauge, one of these days.

If there is pressure build up....when was the last time you flushed the system, with heater on full blast ? Also, was thermostat put in the correct position ? On another Brick, same problem, somehow the thermostat got mangled. It was seated correctly, but looked like the body was twisted clock wise. Go figure.

Enjoy.