383 magnum versus 383 big block

There was an article many years ago talking about this very issue. The bottom line was that it comes down to volumetric efficiency. Basically, cubes matter, and the rest is "tuning" for application. A small block vs big block, cube for cube, will have the same potential as long as the engine can breath. "Where" it makes is power is a discussion, but you all probably know book loads more about that than I do.