Who wins?
I would take Ali by Unanimous Decision. I think Ali would control Holyfield with his jab and Holyfield would have trouble hitting a target with the movement Ali posessed in his prime!
1966 Muhammad Ali vs 1993 Evander Holyfield
Ali would dance around Holy all night, popping that jab with the occasional right hand following. If Ali got caught, well we all know how good Ali's chin was.