I’d love to see it. Kalambay beat McCallum with his movement and defensive cuteness. Monzon would be cute but not the same moving target. McCallum’s best chance is to use his vaunted body attack and not get drawn into Monzon’s web. But Monzon was such a tricky fighter to repeatedly hit clean and I think he’d tie up McCallum on the inside and possibly outstrength him to wear him down. Plus, McCallum’s power at 160 wouldn’t present an imminent danger to Carlos. I see Monzon pulling away over the last 5 rounds after a very competitive first 10.
I think McCallum is technically better, better inside, better outside, better defense and has better stamina. Equal jab. I don't see how Monzon beats McCallum. I don't see anything he does better.