6v did not need/use a ballast resistor (flux capacitor)*
A change to 12v requires - a 12v coil and a ballast resistor (preferably); or, - a 12v coil with an internal resistor, which keeps the points from burning, but, does not allow the starting "advantage" of the 12v-coil/ballast resistor set-up.
* an adjustable flux capacitor must only be adjusted with with clutch-head sonic screwdriver.
Yes, in the end the only difference was bypassing the ballast resister and since they didn't come with one originally I'll remove it. At this point I've decided to stay with the 6v system, unless something fails.