The two greatest of all-time for heavys are 70's and the 90's

Head-to-head is the best way to compare them so here it goes.....

Ali-Holyfield = ALi
Tyson-Foreman= Tyson
Frazier-Lewis=Frazier
Wepner-Bowe=Bowe
Quarry-Morrison=Quarry
Spinks-Tua=Spinks

That makes it 4-2 to the 70's