Ross, understand what you're saying. For sake of discussion, I'm saying modern "big" dual plane like an RPM versus modern single plane like a Victor. Probably no way to really answer the question, so many variables with gearing/weight/etc.
Still tuning on my combo, trying to get it snappier around town. If I can't get it where I want it, may go with the EFI. Lots of choices though, for same $$....could go 445 which I'm sure would pick it up a little too 
Just picked up new O2 sensor in hopes of verifying that my Innovate is reading correctly, haven't been able to trust it after taking a ton of jet out of it and still getting 10:1 AFR.
My guess is on engines that are "on the bubble" between intakes, EFI would get it where the single plane isn't really giving up much down low as it would with a carb, and retain the topend. Encouraging that you've seen real world torque increases with either EFI.
Chilly, first sorry for the book, and it only scratches the surface anyway.
Barry hit on the basic premise of intake runner tuning, length and cross section, that determines volume and a tuned length. If you look up water hammer or inertial tuning, it goes all the way back to the Ramcharger days and you can calculate an intake runner based RPM peak mathematically using runner length and cross section.
Those airflow characteristics are generally fixed, although there are more factors that ultimately effect efficiency even with a given length, for example plenum size and all the various radii (radiuses? LOL) affect how the air fills a cylinder, and of course it doesn't act alone, in the end, even the exhaust affects cylinder fill
Additionally, a torque curve is affected by the range of those runner lengths. We had a good discussion a long while ago on Speedtalk about having matched runner lengths in an intake, or a mix of short and long. Some wanted to focus on the peaks and have them match for overall peak power, others wanted a combo of short and long runners for a flatter curve, it really depends on the end use. For the most part, a dual plane would do the first, the single the latter.
Keep in mind though a single plane usually has overall shorter average runner length so they generally tune for a higher RPM overall, even though a mix of short and long may flatten the curve, the dual plane has a longer average runner length which generally tunes them to a lower rpm (note all the "generallys" everyone has a bit different mousetrap)
The second factor that you bring up is low speed mixture and balance across all the cylinders. Then add the difference between adding fuel at the beginning of the port with a carb, versus near the head and you add additional characteristics. Although I think NASCAR has determined injectors farther away from the head work, and carbs sure make power, but on the same token,by changing location and then controlling it, you can easily get fuel to the intake port when you want it, which helps low end ops.
I can confidently say that I can change a blubbering idle and soft part throttle to a clean one, just by manipulating injector pulse duration, fuel pressure and injector timing. It can be dramatic, even when the calculated amount of fuel isn't changed. That results in more torque, but it would in an dual plane or single plane. Additionally, with the SEFI, low rpm mixture (I assume) is more balanced, but I do not tune with individual EGT or O2 sensors, but it seems it would be
I used to be reluctant to tune over the internet, but I have since learned that some basics can be done and had lots of success. Not long ago,a guy I have never seen sent his *.bin file to me to see what I could do, it ran OK already but not real clean down low. All I did was calculate injector PW and timing based on actual cam events and send it back, and he said it went from fussy to new car like. Peak power surely didn't change but drivability sure did, I had the same results on my 489 which is why I agreed to do it, to both try to help but also validate what I was trying to do with injector timing
So, in the end if the questions are:
Will a heavy Galaxie run well with SEFI and a single plane that is a little too big? Yes assuming the EFI will let you tune it.
Would a fast, small CSA intake like a Street Dominator do better in that application? Probably.
Would you get more torque down low with a dual plane? You should, unless the cross section or plenum is real big or the single plane was much smaller. Although I have not read the article, Barry's dual plane EMC will probably show that the longer runner length combined with mixture control of EFI optimized the whole curve, which is a good EMC (and street car) tactic I'd think
So as Barry eluded too, the intake itself doesn't change how acts with EFI, but the beauty of port injection is that you can play with how the fuel gets to the port and that can tune specific areas to make something work closer to the way you want it
