Tiger, in brutal fashion. Zale wouldn't be able to hold his own against Tiger on the inside, and would be forced on the back foot. Zale lacked good boxing skills however, and would be trying to brawl while being moved backwards, which makes one vulnerable. Tiger by late stoppage.
Tiger is a heavy favourite here. More interesting is speculating about Zale's chances of hearing the final bell. I think he could make it.
IMO Tiger had the much better boxing skills, was more durable, and he was pysically also stronger. He would put his stamp on Zale and fight him on the inside, I would expect a late TKO for Dick Tiger... Tiger TKO 13 Zale
Tiger by Majority Dec. Zale may have avoided some of the great blck fighters of his era ,but he was a tough cookie himself,he would go the route and be competitive,nogreat boxer,but neither wasTiger.