Gnarly - YES, those are such beautiful cars. Is that yours? '64 and '65 are my favorite with '69 coming in a close second. But, I've owned a '72 Formula 400 since '86 and that will be forever my favorite.
As to mods working on carb vs. EFI - what I meant by "carb/FI notwithstanding" is that removing whatever quirks a factory EFI setup imposes, the general rules of increasing airflow through the engine = more power still hold true. Yes, if the factory ECU can't handle the changes or the injectors can't deliver enough fuel or the intake manifold is too restrictive or whatever then that imposes limitations on how far you can go. This is one of the reasons I wanted to stick with a carb'd engine. I'm not into rock-crawling so issues of fuel pouring out at extreme angles aren't something I'm going to worry about. There are a lot more options with carbs and you can go a lot farther with modifications without having to fight a computer.
And finally, about variances in reported data for things like cylinder head volume - It's not surprising to me to see differences of a couple CCs one way or the other with something like that. First, there would be production variances to take into account. There are various things in an engine that the factory is either more or less concerned about. surface finish on a crankshaft, bearing journal diameters, piston to bore clearances, etc. are the kinds of things that are critical and are held to close tolerances. Other things like combustion chamber volume variances of a CC or two aren't as critical and it doesn't pay to try to hold as close of tolerances on those things. Casting core shifts and variances in the final milling of the deck surface of the head could account for a CC or two difference on a fresh from the factory head. Then throw in whatever might have been done to that head over the years. A mill job makes the chamber smaller, a valve job makes it bigger, and pretty soon one guy is saying his chambers are 56cc and another guy is saying his are 60 and they might both be right, especially when you throw in another variable - the technique and equipment used to CC the chamber. The information I'm after is what does Toyota say that head is supposed to be?
I tell you what, the next engine I build and it won't be a whole lot longer (maybe next winter) is going to be measured and analyzed. I paid one shop to do the machine work on my 20/22 hybrid and several years later I paid another shop to assemble it and now I have an engine with only a few thousand miles on it that smokes and rattles and has what sounds like either bad piston slap or a bearing knock on hot restarts. It definitely has more power than a stock 22R but that's about the only good thing I can say about it. Next time around I will personally take the time to measure everything and will assemble it myself and I'm going to use something better than the cheap cast pistons everyone sells. I really like the look of the Wisecos, their dome design makes way more sense than that cone-with-a-cup-in-the-top design all the cheap pistons use. I just need to find someone who can make a deck plate for the boring & honing and find a machine shop that actually gives a damn about doing quality work.