The various types of "high output" coils all work the same way, regardless of how the advertising department for the manufacturer spins it. They increase the current flow in the primary windings to develop a stronger magnetic field, and a higher open circuit voltage in the secondary winding which fires the spark plugs. That's fine, as long as there is an electronic switching circuit in the mix that's capable of handling increased primary current. Points can't do that- - - -no matter how efficient a condenser is used to protect the points, they can't handle current flow more than 5 amps or so. Most "flamethrower" type coils run primary current in the range of 15 amps or a bit more- - - -three times what a set of points should handle. That's OK if you plan to make a few passes down the drag strip, or spend one night of going around in circles, and then change the points, but doing that with a daily driver doesn't make good nonsense. With the engine running with a "12 volt" electrical system, a voltmeter at the ignition switch side of a "resistor needed" coil and a point-type distributor should see 9.5 volts or so to keep the points function ing properly. The upstream (ignition switch) side of the ballast resistor in a system like that will be around 14.5 volts with a good charging system.
BTW- - - -a clean, properly-gapped spark plug fires at about 8KV, so that "50,000 volt" flamethrower will never get to develop its high voltage- - - -once the spark starts flowing across the plug electrodes, it's impossible for the voltage to rise above what was required to ionize the gap and start the skark flowing. Buy a plain old OEM coil and keep the rest of the money you would have wasted on the fancy coil for a few cases of beer!
Jerry
