I recently installed a set of console gauges to my 67 396 and the water temp gauge is reading high. I'm not convinced the engine is running hot as when I turn the headlights on the gauge reading goes up slightly and when I turn them off it goes down slightly. Any suggestions?

 

Bad sending unit?

 

You did install a different sending unit along with the gauge? The gauge won't work with the factory idiot light sending unit.