In terms of mythical matchups, Rocky would struggle against other top heavyweights, mostly because he wasn't a heavyweight himself. I believe he fought at 188 lbs- a cruiserweight in today's world.
He gave up a lot in height and weight....Rocky even had a shorter reach than Floyd Mayweather. He would have given up 60 lbs and 6 inches in weight/height to Lennox and the Klitchko brothers in their primes.
Looking at his own won/loss record, I believe a prime Marciano would have lost to a prime Archie Moore, Joe Walcott, and Joe Louis. I believe Ali would have beaten Marciano and my speculation is that Vegas would have Ali as a huge betting favorite.
You shit-kicking, stinky, horse-manure-smelling motherfucker you! If you ever get out of line over there again, I'll smash your fucking head so hard you won't be able to get that cowboy hat on. You hear me? Fucking hick. -Nicky (Casino)
