Let's Build a 416 with Cast Iron Heads and Manifolds

273 said
Did I say it's cause of stroke length, not it's ability to breath with similar top ends.

Yep, quoted below.

273 said
I see displacement more as a powerband selecter,

I see where you’re going with this and it would be accurate if all the same parts are moved over from a smaller engine. A 340 for example will want to move more air at a higher rpm than a 408 or 434. At the smaller CID and W/the shorter stroke, it will need to turn more RPM’s where it will make the power. The larger 408/434 will need less RPM to move the same volume of air and fuel to make the same HP.

The ability to have an engine turn 7500/8500 is not regulated to its stroke. Though I’m sure I can point to a few engine on the extreme and not of the nature we work with here.