How's it play out at 130, 135, and 140? 147 isn't worth discussing. Obviously welterweight is a mismatch in Pac's favor.
I am thinking Pac slashes Chavez. Chavez wasn't as fast as Marquez and didn't have his countering abilities, nor Morales' reach. If he got close he could obviously do damage, but Pac's speed and straight punches would bust him up. No single left cross would stop Chavez, but five in a second, round after round just might. Chavez' best chance is at 130
There's zero chance of Pac "stopping" a prime Chavez. But could he win a decision? Yes. His speed would indeed be problematic for JCC. Probably why Duran vs Pac would be the ultimate matchup. Both figure to be a bit too quick and dynamic for Chavez.
Manny is more dynamic, but he’s never fought anyone with the ability of Chavez. I think Julio wins at 130 and 135, and Manny wins at 140 and above.