With my experience with "Electronic Spark Control" on my '80 Newport 360 2bbl, my suggestion would be to do a rebuild on the TQuad with a quality kit AND use the thick OEM carb base gasket (rather than the thinner "cardboard" gasket in most kits).
The ONE time I thought I was having a "lean burn issue" (by '80, the ELB had evolved into ELC, same thing without the "lean" carb orientation), it was not the computer or anything related to it. It turned out to be a poor terminal connection at the plug end of ONE spark plug wire, from a set of wires I'd put on the car after I bought it. Fixed the wire end and no more problems.
In chasing that intermittent problem, I consulted with many Chrysler techs and did my own research. System grounds are very important, but all of mine were intact, plus I cleaned the mounting surfaces for the best conductivity. Like later engine management systems, it's all about "volts and grounds". If the "electrons don't jump right . . ." the computer gets bad/poor information to made decisions with.
By observation, many people who do these conversions end up with a mis-matched system. To me, the best way to do it would be to start with the Mopar Perf Electronic Ignition Kit. That gets you the whole list of things dealing with ignition system. Just put a normal or aftermarket control box with it, other than the Orange Box supplied with it. Then, get a new carb. If you want a pretty-much bolt-on spreadbore, then then TQuad look-alike Street Demon carb might be a good choice. If you want to do an aftermarket intake and squarebore carb possible Edelbrock Performer dual plane), then the Edelbrock AVS2 might be the choice (Summitt has a good price on them right now). You might need to rewire the existing electric choke system, but that's a minor deal.
Doing it this way, what you end up with is a new distributor with a KNOWN advance curve (performance oriented) AND a carb with a KNOWN metering characteristics. "KNOWN" is a key thing as this makes things more "plug and play" trending toward "good results" than using a reman distributor and reman carb, both of unknown internal specifications. Even if you get an aftermarket new distributor, you'll probably have to play with the mechanical advance curve. PLUS the parts in the distributor and kit are OEM Chrysler, so you know where to get parts for it, if needed.
The whole deal about "Lean Burn" was a special-calibrated carb for 16 to 1 cruise A/F ratios (leaner than 15.0 decreases HC to basically "zero", which is why no cat converters were needed to pass federal emissions specs) AND an ignition advance curve to work well with that leaner mixture. When new, those engines really sounded good, as in quiet and energetic. So I know the basic set-up was good to start with.
When anything went wrong, many were very quick to condemn the ELB system, not knowing that something like that would be commonplace 10 years later.
NOT sure about that mass of capacitors and such that's been added to the car. Possibly somebody was trying to chase an ignition noise issue?
One thing about TQuads, although they are a "metering rod" carburetor, with a central "power piston" that runs the metering rods up and down (against spring pressure), when you get the throttle plate off, you'll notice a white plastic, rectangular "paddle" that is operated by a cam on the primary throttle shaft, This makes sure the power piston moves with the throttle shaft. A default mode should the power piston spring fail?
When the power piston spring fails or is not re-installed when the carb's part, it will keep the metering rods "DEEP" into the main jet, resulting in a very lean condition, where all acceleration ends when the accel pump shot is used up. I had that to deal with on my father's '69 Chevy pickup, when it was relatively new. He drove easily, so the power piston would stick in the "economy" (down) position. IF you drove slowly such that no additional mixture enrichment was needed, it was fine. When you throttled into it, after the pump shot was gone, it fell on its face until rpms could build enough (at WOT) for the secondaries to crack open, adding their own fuel to the mix.
Several years ago, a customer called up asking what might be wrong with a '78 Chrysler that belonged to one of his gas customers. I asked what the issue was and I ended up going over tro see what it was. A 30K mile dark green '78 Newport 4-dr, dark green cloth interior, garage kept, and very nice. Starting, it sounded decent. Driving . . . on initial acceleration (at ANY throttle opening), you could have jumped out and pushed it away from a red light quicker than it would move by itself. But, when the rpms (after a near-WOT start) got high enough, it was like the afterburner kicked it. It did this reliably, too! The metering rods were moving, timing was correct, but it all started after the grandson put a set of plug wires on it. DING DING! A check of the firing order revealed that he mixed #5 and #7, which fire consequentially. As they are near each other, probably not too hard to do. When the two wires were swapped into their correct locations. It ran flawlessly AND faster than you'd suspect a std cam 400-4bbl (base engine) would in that car.
So, ignition issues can act the same as fuel system issues, sometimes. Some might disagree, but I'd say "Don't condemn the ELB automatically." What you describe sounds like a carb issue, or at least THAT's where I'd start first. Then, too, some people don't think too much of TQuads, either. Funny thing is that when you open up a Street Demon, it looks like a copy of a TQuad, right down to the tube from the accel pump to the accel pump discharge housing!
You can invest the price of a good carb kit and OEM base gasket to see if you need to go farther. The TQuad isn't very hard to rebuild. I like them much better than the Rochester Quadrajet. IF the carb issues don't fix it, you can do the basic look-see on the ignition system. If you end up doing the conversion, just get the items I mentioned above rather than otherwise, please.
Your car, your time, your money. I respect that.
CBODY67
