1952-59 Ford ballast resistor confusion

I'm getting ready to convert to 12 volt on my 54 mercury.
have new wire harness, single wire GM alternator, battery, starter relay,
However... I'm so cornfused with all the info I'm finding on ballast/no ballast resistor, coil with internal resistor or without... seems all contradict each other.

Help please, before the men in white coats get here.. I did the conversion on my 53 ford truck about a hundred years ago... now I'm old and senile and cant remember and the contradicting "articles" aren't helping!?@#$$

 

I converted my 55 customline to 12volt and it was pretty simple and cheap.All 6 volt coils need a ballast but get a true 12 volt coil like I did and dont use a ballast . I forgot the part # but google 12 volt coil . nappa auto parts has them ,along with other auto stores

 

the NAPA part no is IC14SB
autozone part # uc15

 

Even with a 12 volt coil you need a ballast resistor. Either a separate one or an internal one in the coil.

Otherwise you can burn the coil and the points up.