On my 45-2N I run a 12V, positive ground generator, wuth voltage regulator and a 6volt (1.5 ohm) coil, with 2 resistors (!2 to 6 volt, ballast resistor. I like this setup, as the front mount coil is subject to intense heat from the radiator and this keeps it cooler. Ialso get 12volt hotter spark at cold statup. The positive ground also directs the spark to the center electrode of the sparkplugs. Points have also faired well in this setup. On my Ford 600 sidemount, I however run a true 12volt coil, with ballast resistor (don't really need it), with switched wires on coil for changing polarity, as I use a Neg ground polarity alternator, with internal regulator. This setup also has all the good characteristics, as above. The "Tin can sidemount can stand the heat better.
Charles KramminSW MI