No, this is all current stuff. I don't know if advancements in engine power have uncovered shortcomings in CDI or advancements in circuitry have made inductive stuff better than it was or what.
I don't have a dog in the fight, I just found the discussion interesting.
There is ABSOLUTELY NO QUESTION that coil on plug is a very good idea.
It was a good idea when Porsche did it back in the late 60's early 70's,
but the electronics were NOT reliable enough or accurate enough to make it viable in daily drivers.
The system was POWERFUL, no question,
but it was also VERY trouble prone, took constant maintenance, and the plugs of the day wouldn't keep up...
We've tried all kinds of stupid stuff down through the years,
4 sets of breaker point on Siamese coils,
8 sets of breaker points on 8 coils,
8 electronic triggers/modules on 8 coils...
(digital control wasn't around back then...)
What I mostly found out was the slop in the timing chain ruined any gains.
Add in some really LOUSY 70's & 80's machine work on blocks & cranks,
Where the crank throws didn't come up to TDC on all cylinders at the correct crank angle,
And all that combines to pretty much screw up anything you might try to be doing with the ignition...
So having a set of cylinders 3 to 6 degrees off on the crankshaft screwed up even crankshaft triggers...
Things are MUCH better now with CNC machining instead of some hungover guy using worn out holes in an indexing head to locate the crank journals when grinding the crank!
Lets face it,
We have different length and different volume intake runners,
We have #5 in full intake velocity when #7 starts to draw, so #7 gets starved,
We have fuel introduced at the beginning of the intake tract, so fuel gets to settle out along the way,
We have low pressure fuel introduction, and actual "Suction" system putting fuel in the system, so we are a LONG WAY from proper atomization...
We have sloppy timing chains, lash in the camshaft/distributor gear sets,
We have vacuum issues...
Now, if we were using equal length & volume intake runners with mass air flow sensors, so we not only know what VOLUME of air is entering, but the DENSITY (oxygen content) as well...
We were injecting that fuel right at the intake port,
We had high pressure injectors for proper atomization,
We had precise control of the fuel entering the air stream, Resulting in the same fuel/air mixture in every cylinder...
We had combustion chambers that had 30 or 40 years more design refinement,
And we were running MUCH higher compression with much LEANER fuel mixtures,
I think a coil on plug ignition system would be worth the money...
We don't, so we work with what we have...
Hopefully, cost effectively since none of us have a $50,000 engine budget...
From what I was also reading lastnight, seems like the long duration powerful spark from the HEI is better than the thin extremely fast multiple spark of the CDI for our applications at least.
And my clone HEI is using what looks like aluminum terminals for the plugs wires... instead of some quality brass terminals! And I've had to clean up the terminals under the cap a few times as they get some kind of galvanic corrosion on them?
Did your research uncover the ratio of decline vs. RPM/saturation times with the HEI?
You are getting less than half the spark energy at 2,000 RPM you were getting at idle due to shorted saturation times as RPM rises,
And with an HEI clone with plug gaps opened up to 0.050" or 0.055" like most of them recommend,
You are wasting most of the spark energy discharge in 'Rise Time' building voltage,
And wasting time building high voltage numbers WASTES amperage & duration times.
Those guy ALWAYS quote the highest outputs,
They NEVER actually give you the spark discharge data in full as RPM increases.
The HEI drops off faster than most of the 'Factory' electronic ignitions, simply because of coil size restrictions.
In 1974, it was a big jump in spark energy over breaker points,
But compared to modern single spark discharge ignitions from the past 10 years, it's a mutt.
Not a galvanic response causing that 'Corrosion'.
Aluminum is a pretty good electrical conductor when it's clean and shiny, and isn't exposed to an arc.
Aluminum is porous, so the spark discharge 'Tunnels' into the porous aluminum terminal,
Burning that aluminum into aluminum oxide (Oxidized Aluminum) as it does.
Aluminum oxide is NOT considered a conductor for our purposes.
Aluminum IS, however, cheap and easy to work with, works pretty good for a short period of time.
BRASS does NOT tunnel, it also doesn't oxidize nearly as quickly.
When brass overheats, it 'Heals' as it cools, instead of oxidizing.
Brass is more expansive and harder to work with since it's more dense, so the cap makers don't like to use it as much...