Would a starter for a 1958 Buick Roadmaster 75, 364 CU IN, V8, be compatable for a 1948 Roadmaster 71. Other than the fact that it is a 12 volt starter into a 6 volt system. I have a 12/6 battery and can run both 6 and 12 volts. Are there any after market starters that may be compatable?