this is not a serious matchup Tunney destroys Thomas tko mid rounds or wins every round in a decision!
I like Thomas' jab and size to get him home via decision. He'd frequently stunt Tunney's attack and i think that jab would be the story of the fight.
Michael Spinks sometimes weighed in around the super middleweight limit before he stepped up to heavyweight. Gene Tunney had outgrown the light heavyweight division by the time he fought Dempsey. Yes Spinks had access to modern methods of bulking up, and he was the first fighter in history to do it by the way, but take that away and he was never much more than a super middleweight.
In retirement Tunney towered over guys like Patterson and Frazier. Tunney and Dempsey look around as Tall as Ali going from photos. Not that height is that big a deal, I do however think heights became less accurate as time went on. Would not surprise me at all if Tunney walked out of the time machine and turned out to be taller than Spinks. And Thomas for that matter.
I would pick Tunney to outpoint Thomas to a decision. But Pinklon’s excellent jab would keep it a close fight