Let' consider Vlad and Vitali agianst the all-time HW greats more fairly...

when you mention jack johnson losing to willard, you do realise that johnson would of won that fight if it wasn't for being over 20 rounds? do you think wladimir can box for over 20 rounds?

 

Not if the colored folk are over 40.

 

You have some good points.. In my opinion they do get under rated. But they would by no means dominate the 70s. there's too many fighters back then that would defeat them. I can name a few; Ali, Foreman, Frazier, Holmes, Norton, MAYBE Lyle, I might even say Joe Bugner haha. Chuck Wepner could probably go the distance.. Not sure. Oscar Boneavana would get stopped, Jimmy young MAY outpoint him. Leon spinks would get killed no doubt.
in the 60s, hmmm.. I'm not sure. Ali in his prime would definitely win against the Klits. Sonny Liston would do well, it would depend how the Klits fought him. Floyd Patterson would probably get knocked out, Goerge Chuvalo would go the distance, and Henry cooper would get stopped. Once again I think Frazier would smother them. Brian London would get killed.
I can see them dominating the earlier eras, simply because there were no big, skilled, hard hitting, and intelligent heavyweights like the Klitschkos. It seemed like in the 1900-1950 there were no heavyweights like the klitschkos. However, I think Rocky Marciano would beat them. Rocky would never give up, despite his size disadvantage and reach. He obviously hits harder then them, and had stamina advantages.
Joe Louis; I can't predict that. Based on Wlad's shaky chin, I think he would knock him out, Can't say the same for Vitali. He's just so tough.
80-90s.. I can't see them doing well there either. Larry Holmes is still dangerous, and there's Tyson, Lennox Lewis, Bowe, Morrison, Mercer, Cooney, an old foreman, and Rudduck. Plenty of guys that would give the Klitschkos a fight.
Just my take on it

 

Hard to picture a prime, young Foreman being any more powerful or fit than he was. He was a beast by the standards of any age. I'd say he was at his physical peak for the Frazier and Ali fights. Doubt you could improve upon that physique in any significant form even if u used the best technology from today.

 

The giant heavies with skills are relatively new to boxing. It only takes a quick glance to see the Klitschko's are much better than the Jess Willard's, and Primo Carnera of boxing in terms of winning rounds.

 

Vitali would win a belt in any era. He's tough, strong, powerful puncher, great chin, and has size in his favor. I don't see him not winning a title. Wlad is a different story all together. His weak chin and lack of toughness when things get rough, would be his downfall. Fighters like Bowe, Holyfield, Tyson, Lewis, Foreman, Briggs, Bruno, Mercer etc... Would all be willing to test Wlad's weak chin and see what happens. Wlad was blessed to just miss that era by 5 to 10 years. We have already witnessed him struggle and fall apart at the seams against much lesser oppenents. Fighters like Peter, Brewster, and Sanders, all made him panic and lose control. I truly believe Wlad would not survive if his prime was in the 90's.