Big horsepower 318 builds

My view is simpler than that.

In “most” cases, it’s easier to get the larger motor to “use up” the cylinder heads.
In that video, they put 345cfm heads on a 302 and never even got close to using up the available flow.
On my old 451, I made about 170hp more than that motor did out of my 340cfm heads with 2.19 valves(without a ported manifold like the Ford had).
And on another build that was yet another 106 cubes...... with slightly lesser flowing heads of the same type as what I had on the 451....... it made another 70hp.

So that motor made 235hp more than that 302 did, using heads that flowed 337cfm, and didn’t have the benefit of a ported intake manifold.

Using some simple formulas...... it would take the 302 nearly 11,000 rpm to use up a set of 345cfm heads.
On a 451 it takes 7300rpm...... which is much more within reach for most builds.

The old SuperFlow formulas show the 270cfm heads are capable of 555hp......... and that on 416ci....... they would peak around 6200(made 561@6300).
The same formulas say it would take 8000 to use them up at 323”.

The 311cfm heads on the 302 Chevy are worth 640hp.
To use them up on a 302 would take 9850rpm........ but 7330rpm would do it with a 406.

In the 30 years I’ve been dyno testing motors....... I have seen some motors follow formulas pretty well....... and others that just don’t.
But I don’t recall ever testing a small-ish cube combo, that fully exploited the potential of some large-ish, high flowing heads...... and could do it at a moderate rpm(NA).

To me, the fact that the TQ goes up as the engine gets bigger is usually just an added bonus.