[19Fordy]

Last year I installed the Pertronix 12V conversion kit required for my 1953 Ford Mallory distributor and used exactly what the Pertronix folks recommended just to avoid the problems you are facing.
For the Pertronix conversion kit I purchased , Pertronix told me to use the Pertronix chrome flame thrower coil # 4001 rated at 1.5 ohms. It does not use an external ballast resistor. So far, the system works great. They also make the 1.5 ohms coil without the chrome cover. It has a different part #.

I also have the same #00012 coil that you have and did not use it because I figured Pertronix must know what works best with their conversion kits.

Prior to this I had been experimenting with various coils at the advice of many Fordbarners to no avail.

Call Pertronix and ask what coil you should be using.