keep oin mind thatt he front mount square can coils NEED the oe ballast resistor on 6v.
later N with 6v round coils DO NOT need a resistor to run on 6v.
what exactly are you trying to do.
a napa ic8 is a 6v round coil for a later sidemount N.. it needs no resistor to run 6v. an ic14sb is a 12v round sidemount.. it needs no resistor to run on 12v.