JOhnson, given time to adapt to a 1980s set of rules, would find a way to eek out a decision. I am not sure Norton can manage the reverse time trip win.
Norton frustrated Ali in all of their fights, arguably winning 2 out of 3. And older Kenny pushed a prime Holmes to the brink. He wiped out a clever counterer in Quarry. Johnson has nothing like that on his heavyweight resume. Tho my heart wants it otherwise, Johnson just doesn't have the physical tools to bulldoze Norton nor do I think think he possesses otherworldly skills by 1970's standards.
Pretty much how I see it. I think Norton's jab would easily find its mark vs Johnson low guard and a stationary type of defense as easily as Jack O'Brien's jab did. Not only did Norton have a good jab, his body attack was murder. Johnson didn't hit hard enough to pull off a sneaky type of KO, nor was he active enough to win on points. I like Norton here via later round stoppage.
Johnson at his best stops Norton after ten rounds. Johnson has the all time great defense at distance....Norton would find it very difficult to land a blow. In close Johnson would smother and control Ken while landing his very powerful uppercut.
Was Johnson's defense at distance better than Ali's? Did Johnson prove this against better heavies thay Ali did? Did Johnson prove this again well schooled heavies with 81 inch reaches and excellent jabs. Did Johnson beat anyone near as good as Ali, let alone 2 times? Do you really think that Johnson was stronger than Norton, such as he was stronger than a Burns or OBrien?
Johnson had a far better defense than Ali. Really not comparable. Ali relied on speed. Johnson speed and great technical ability. How Norton did vs Ali in no way predicts he would do well against Jack Johnson.