1938 Ford Truck Starting problem

[classic car repair]

Well I'm back, I have a 1938 Ford Pickup 1/2 ton, V8, I replaced the Ignition Ballast resistor (NOS), run new wire from the key switch to the resistor, run new wire from the resistor to the coil, When it cold, it start right up, when it warm up to about 160 deg, and I start stepping down on the gas, it will back fire at time, then it will die out or not, try to restart the engine, will not start, if you jump the resistor and have full 6 volt, it will start, I'm thinking it's the coil? but I can be wrong, If you turn off the key at high temp, it will not start too, but now it back fire when it hot at time but not all way, when stepping down on the gas, Thank You