I have a 55.1 which would have been made with a 6 volt. It has a solenoid starter. It may just be a matter of switching the gear on the starter with a gear from a 6 volt starter and installing the 12 volt. I think my starter came from a 12 volt 6 cyl car. Change the little gear. It seems foolish to go to the trouble of changing the flywheel. - Scott
