I went out to my storage shed and dug out some old service manuals, including a 1978 Ford manual, to verify that the Duraspark II is directly connected to a 12 volt supply, and it is. The preponderance of the wiring diagrams I could come up with on the internet also show this, but I wanted to verify it myself.
I knew that the Duraspark module could not be connected in parallel with the coil, after running through the pink resistor wire. This would cause the Duraspark module to function from a constantly changing voltage source, and always less than 12 volts. Every time the coil windings charge up they place a load on the resistor wire and reduce the voltage to both the coil and, with this wiring diagram, to the Duraspark module. Additionally, the Duraspark module will add it's own load to the circuit, further reducing the voltage to both the coil and module.
As I suspected, the wiring diagram from NPD is not correct, nor is the statement that the module has to run through a 1.4 ohm ballast. The red wire that connects to the module must be connected directly to a 12 volt keyed source. The positive (+) wire that goes to a stock coil should be connected to the red/light green wire that connects to the pink resistor wire.
The white wire is connected to either the "I" or "S" terminal on the starter solenoid. The purpose of this connection is to retard the timing during cranking, with the blue grommet Duraspark II module. The brown or red/green wire that supplies 12 volts to the stock coil during cranking should remain connected, also.
EDIT: After thinking about it some, the brown or red/green wire that supplies 12 volts to the stock coil during cranking should NOT be connected to the same terminal as the white wire, or it will back feed into the white wire to the Duraspark module, potentially affecting timing. I believe it should only remain connected to the "I" terminal with the white wire connected to the "S" terminal. The "I" terminal provides 12 volts during cranking, only. When the brown or red/green wire remains connected it has the reduced voltage during run, when the coil is connected through the ballast resistor or pink resistor wire.
If you use an after market high performance coil or a Ford e-coil then bypass the resistor completely for both coil and Duraspark module.