The conversation evolved fron rat bastid telling me that a lower torque higher rpm engine will always make you go faster than a higher torque lower rpm engine, even if they are equal horsepower.
Since cylinder head is the main limiting factor to horsepower, and displacement is the primary factor in making torque. we started talking about the hypotheticals of less/more displacement with a given cylinder head.
Agreed, There's nothing stopping them entering with big cubes but it gets cost prohibitive.
A 414ci would need 574hp to make the same 1.388hp/ci as this 371 did. That's at the upper end of the potebtial of a small block on pump gas.
In the other hand, A 273ci mopar could be pretty competitive in this competition. It would only need to make a peak hp of 379hp to have the same peak 1.388 hp/ci
I know which I would find easier and cheaper to built!