Sun tachometers of the day had a sending unit under the hood and the meter itself, in a bullet shaped chrome bullet, was usually mounted on the steering column. A friend had a 51 Merc with one. It looked good, but he wanted it to to help him shift at the optimum RPM. Unfortunately, it drew so much current from the points that the engine wouldn't rev very high and he had to disconnect it when he wanted to race.
