Foreman even at his best wasnt a quick puncher. Lets not forget Tyson had very good defence and quick headmovement which imo would give Foreman alot of trouble trying to hit Tyson. Tyson was also very different in his prime to anything Foreman had faced, he was quicker then Frazier, more powerful then Ali. I would go with a Mike UD as IMO he had the superior skills.