That flasher will most likely flash fast. If that is not an issue then use it until it quits. Should be able to put a 12 volt back in the same location. The mounts did not change. The pin out is the same. Might be a bit taller or shorter over all and that should be no problem. The flasher works with current and heat. More current is more heat. When the "bimetal" contact gets warm it moves away from the power contact and then cools off and moves back in to the power contact. Simple as a house thermostat. ....in the old days any way.
