Balast resistor or no?

If you have the same coil as listed in post #10, it says NOT for elec ign.
However it should work ok with the factory ballast res iiiiiiiiiiiiiiiiiiiif your box is an inductive ign box [ similar to, or same as Ch ECU ]. It will work because the coil sees the box as merely a 'switch' that switches power on/off like the points did. CD igns [ MSD 6X boxes etc ] work differently & are not compatible.