...the old adage that "there's no substitute for cubic inches"? There seems to be a lot of expertise on this site and you tend to agree far more often that, let's say, a panel of economists!
Some article, years ago in Hot Rod said, numbers being equal on paper, (i.e. torque and hp), 450 hp form 450 cubic inches was a heck of a lot more grunt than that wrung out of 350 cubic inches. "Horsepower" v.s. "Ponypower", in other words.
Reading this, I assumed it was felt that the power from the big-cube motor arrived earlier than in the (necessarily?) higher-revving, more highly stressed motor. I thought the power data was equal, if it had the same numbers, it had the same power. Another article, in Motorweek, extolled the virtues of freer breathing, more radical cams, larger valves, etc. in smaller engines...and that power thus derived was IN NO WAY less real than that derived from big cubes...what say ye wise men? I would be very interested, as I'm leaning toward a "square" engine with c. 418-427 cubes (Dart block) ....