I have my new 67 Midget running now. It has been converted to GM alternator, but only producing 12.5 volts at the positive battery lead and the alternator "Big Terminal". Were some of these 1967 Midgets negative ground? I've read several other posts about alternator conversions, etc. Should I replace this one? Doesn't see /ubbthreads/images/graemlins/driving.gifm to be putting out.