I'll go for Lewis' right hand and Tua's left hook. Guys, you have to account for size and weight! Shavers was a cruiserweight by todays standards... Foreman could crack as well.
In terms of absolute power? Shavers for certain. Norton, Ali, Foreman, Ron Lyle, Tex Cobb, they all said he was the hardest puncher they all ever fought.
although he never weighed much more than a middle,bob fitzsimmons would have to be up there.pound for pound he's could arguably hit the hardest of them all.
Lennox Lewis when he executed the right cross, has a definite argument. Often, he held back. It was a great punch. On balance, though, i'd go for foreman.
I have heard a lot of stuff about power from many old timers and i know from good source that you'd have to go a way to punch harder than Archie.... Shavers and Foreman have great percentage ratio , and are proven KO artists, but it really is like a guessing game, if you never tasted that leather from the men in question.. Hatchetman Curt Sheppard was said to be one of the altime great powerpunchers , it was just a natural gift he posessed.. either way, i would no like to be checked out by the fists of Archie, Curt, Earnie or Big George.. They got... as the fighter from the deep south may put it, too much sauce on that thing..
Joe Lewis anyone? What about Jack Dempsey? I love how both of them had punches that looked weak on TV but wow did they do some damage.