Without getting into more theory...
and in an attempt to get the OP running smoothly again, I filched this from the 'net.
It simply underscores what has already been stated - if the rest of the system is suspect, worn etc - then no add-on 'electronic' box can solve the problem.
It is a long read but at least it doesn't wander off into the classroom muttering about electron flow and all that other stuff no one cares about.
"Fitting electronic ignition is a great idea ? but it will only perform as well as the rest of the ignition system will allow and with many old worn out classics, that?s not too good at all? So sort out your sparks with a thorough overhaul at the same time, starting with the distributor.
A somewhat crude device, electronic ignition will only counteract so much wear; if the spindle, bearings and the auto advance are all clapped out, it will lead to timing scatter and you?ll never get the engine to perform right.
A good diagnostic engine tune-up will discover whether the distributor is failing under high revs. If it is, them have it overhauled or replaced (there are specialists who deal solely with distributor repairs) otherwise you?re wasting your time and money on any further upgrades.
And talking of upgrades, any serious performance tuning of old engines means that the distributor?s auto advance usually needs to be re-calibrated with different springs and bob weights. The higher operating power of an electronic ignition will usually find the weakest link in the system - and it usually means good-bye to tired old ignition leads that may be years out of date.
Although you may strike lucky at an autojumble and find NOS (new old stock) carbon graphite period leads, it is almost essential to go for today?s silicon type designs to cope best with the added zap! Talking of leads, remember that any dodgy ignition wiring can lead to a higher than desired resistance in the circuit, resulting in weaker operating voltages. So ensure that the wiring is in good shape and that all connections are sound, tight and corrosion-free if you want to get the best out of it.
The ignition coil usually works or it doesn?t. Sports coils used to be very popular back in the old days as they provided a fatter spark (a typical coil would boost the 12v input up to 40,000 volts at the plugs). Sport coils are a lot harder to get hold of in high streets now but you may strike lucky at an autojumble.
Ditto second-hand electronic ignitions, although be careful here as you are buying an unknown quantity and they can be more expensive to repair than their worth plus obtaining the base plates to switch over from cb points to a trigger design may prove hard for some engines. Most classic car enthusiasts use copper-cored spark plugs these days; you can still get cheaper metal cored types but don?t be such a stickler for originality!
With electronic ignitions you can usually extend the spark plug gap a touch more and so benefit from a fatter spark. Any of the leading electronic ignition companies will help with additional tuning tips and after fitting, it is probably best to have the car set up on a rolling road to fine tune the engine; in many cases the ignition timing can be individually set for that specific engine under load for optimum effect."
Hope that helps.