I could see it going either way, but if I had to put money on it I would go with Louis. Louis showed to have a weaker chin, but he did fight bigger fighters during his day and just exposed their flaws. I think that Louis would have been able to punch through the defense of Foreman and keep him off balance. He could have worn him out too.

Foreman obviously had the power to really hurt Louis so that is always a huge factor. He would make Louis much more hesitant to counter for fear of getting hit with another counter.