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.

You cut the wire and strip the insulation so there is about an inch of bare wire exposed on both pieces. Tie the stripped wire into the button holes diagonal to one another so as to create a gap for the spark to jump. I've seen them placed on an individual plug wire to help an oil fouled single plug. 

Gene, thanks for the answer! My Daddy told me years ago about creating a spark gap to make Ford A-Models run, but he never told me how it was done. I remember asking him one time why it made them run better and he said he didn't know, it just did. The part about building up the voltage in the coil to create enough power to jump the gap makes perfect sense. I miss my Daddy, he's been gone 33 years now.