I know this has been done to death. But I don’t understand why Flamethrower coil fails. Their tech support say DO NOT USE EXTERNAL resistor.
I have a 57 Tbird 312 running all stock. I do run an alternator. Output is about 14.28 volts. Holley 4160 4 barrel carb. I have pertronix ignitor 1 Module. The car runs well.
A few years I installed a Flamethrower coil without external ballast as per instructions and tech support. The Flamethrower has an internal resistor. The engine performance was much better. Better throttle response from a stop, hardly any exhaust fumes and clean plugs indicating a much better burn. The problem is the coil without the resistor gets very hot and fails. If I run it with ballast resistor it will last but defeats the purpose. Is there a voltage loss to the plugs when using a ballast resistor? If so how much.
I am currently using a MSD 45,000 V Blaster II with external resistor - again runs good but would probably get better performance without resistor.

The Brillman Company makes a coil EB30SS with 55,000 V that must be used with an external resistor maybe this is an option
Any suggestions or help appreciated.

But after about 1960 they stopped using an external ballast resistor and started using a resistor wire. I've has a Pertronix I in my 66 mustang using the stock resistor wire and stock coil for the past 20 years, it has worked flawlessly. My 57 I have a Pertronix II with an epoxy coil and no ballast resistor with no problems.