others -- Still would like an answer to post #36 above.
Apples & Aardvarks.
All the formulas are geared around WOT acceleration, and have little to do with what you're theorizing.
IMO, on your intake, the plenum/runner line is more vague. And practically irrelevant.
A bent 8 isn't an inline 6, and each case is different anyway.
Some manifolds, on certain combos, like a split plenum. Unless it's a common combo, there's a lot of trial & error. Mostly error.
Stronger mixture signal seems the goal, and the ways to get it are several.
Splitting the intake, more thoroughly.
Reducing plenum volume, as FTF and I have mentioned.