This is a real good match up.
I have to admit that I never had a whole lot of love for tunney because I liked Dempsey so much. But I've since read the biography of Tunney & he really was a GREAT fighter! He's still not one of my favorites, but I under-rated him back in the day.
I'm a big fan of Marciano. But all the guys who fought Rocky were either old or not really a serious threat to beat him. Charles & Walcott were old & they still gave him trouble. That right there is a big deal to me.
I'll take Tunney by a decision. Of the two, I like Rocky much more, but I have to respect Tunney's talent.