We must keep in mind that Ali was, almost always, the taller fighter and in over half of his fights, the heavier fighter. He does not have these advantages in a time machine battle in the land of the giants. He does, however, have chin access of the kind Frazier had on him, so look for some disasters.
Nikoli Valuev would grant Ali a rare first round knockout if he wanted it, something his showboating ego and sadistic frame of mind did not value. I’d look for a 4th round KO via right hand with Ali demoting the giant titlist to a four round fighter in his after fight commentary.
The most dominant post-Ali heavyweights were Holmes, Tyson and Wvlad. The mechanical Wvladamir would fall easy prey to Ali, with a 7-8 round TKO stoppage, possibly because of a cut or exhaustion.
Vatili, Wvlad’s older brother is another story, with the highest work-rate among heavy-handed heavyweights ever seen in the ring and an iron jaw. His only loss was to light-hitting Chris Bird due to a shoulder injury. This would be Ali’s greatest test and it’s a pick-um fight, probably resulting in a trilogy.
Tyson Fury is too cute by half for a man his size and his fights with Ali would be stinkers, a pity-pat draw and a trash talking split decision. You can’t put too dastards in the ring and expect anything good. Ali would have the ability to go for the KO against the big man, but as such an intelligent fighter, it is unlikely that he would go for the kill against a slickster of this size and would be content to out point Tyson at jabbing range.
The Punishing Art
I'll just leave this here:
villages-news.com/wp-content/uploads/2016/02/Wilt-Chamberlain-towers-over-Muhammad-Ali-600x415.jpg
That was such a great picwhen Ali said Timber, Wilt erased all thoughts of the hyped what-if bout between the two.