As the years go by my temp gauge keeps reading hotter and hotter. I know I'm not running lean, I always set my timming in the same place, and the engine doesn't feel or act hot. Before I start the car already the needle is almost in the green, and when running at highway speeds its a couple of degrees left of the "H". So I'm thinking calibration, is this possible? The thermostat is fine etc....I just wnat to calibrate the gauge.