I have a 65 Falcon 200-6 std. The engine as well as the complete car has been re-done. I am still unable to get the temp. gauge in dash to work. I bought a hang on for $20. It was showing me that it was running up to 230. the mechanic said the gauge was 20 degrees off. I went and took that one back and bought one for $30. It was reading the same and I thought there was a heating problem. finally I got one with the gauge on the radiator cap and it never got over 185. The hang on one was still reading 235. these gauges we buy at O'Reileys, Auto Zone, etc I don't think are worth the powder to blow them away. I dont believe that I have a overheating problem. If this engine was really at 235 degrees it would have already been dropping all the fluid on the ground and possibly locking up the engine. Always get a second opinion.
