I agree, torque and RPM are equally important in making horsepower.
I do think though that for a car, sacrificing RPM to increase torque is a beneficial trade-off for increased performance. This is the appeal of a longer stroke.
If we were talking motorbikes, or go-karts.. sacrificing torque for an increased RPM may be more beneficial. Probably why diesel motorbikes aren't popular.
I'm not really aware of any top end configuration that would make less horsepower by being bolted to a larger displacement engine.
Would you mind elaborating on this for me?
Having an additional 20ci is objectively an advantage.
Whether it's a "big" advantage is relative.
As you get closer to maxing out an engine's potential, the gains get exponentially smaller and cost exponentially more.
Let's imagine our A-body cars had mostly came with 440's from factory.
There would be very few people who would go to the effort and expense of swapping to a smaller, rarer small block engine which also takes a different transmission.
It'd be 440's all day and twice on sunday.
Now, let's instead imagine that you could go to a wrecking yard and pull a 440 from a 2001 ram with closed chamber heads, roller cam, 1.6 rockers and basically bolt all your factory accessories straight on to your 340ci engine.
Again, it'd be 440's all day!
You're right that larger displacenent engines usually have bigger bores, but I'm going to have to disagree that that bore size is the reason they have more potential.
The reason bigger displacement engines have more potential is that they are bigger displacement. And bigger displacement makes more torque.