Besides the brake switch, the original temp gauges on an AD have been the most reliable item I have encountered on ANY vehicle I have owned. Every one I have dealt with read right on the zero of the 180 mark once warmed up (except once when the original brass accordion-style thermostat on my '52 216 stuck closed and sent the needle to the peg. It did function properly after that however). As long as you find one with the sensor bulb and tube intact, you should be good to go. The gauge decal set is inexpensive even if you only need the temp decal.
Carl


1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission