So, you presume the car is overheating because the gauge in the instrument cluster is reading really high, is that correct? That gauge is fed by the CTS (coolant temp sender), not the ECT. The gauges are known for being wrong - my red-headed mistress (red GT) reads really high as well. If you have a code reader that can read PIDs, you can see the output of several sensors, including the ECT. It is possible that the engine is not even at operating temperature yet, and the instrument cluster gauge is wrong.
The higher-priced Autoxray code readers can read PIDs, it's well worth the price. The one I have (Autoxray 5000) has cables to read codes from Ford, Chrysler, GM and some import OBDI and OBDII cars. Well worth the investment.
The CTS is a small brass sensor screwed into the intake just off to the right, on the opposite side of the distributor from the ECT. It has one single wire leading to it with a 90* rubber plug on the end.