No catchweight allowed. De La Hoya is at his best at 140-147. Julio Cesar Chavez is at his best at 130-135. De La Hiya has some decent wins at 135 (John John Molina, Rafael Ruelas, Genaro Hernandez) Chavez has some good name wins at 140 (Roger Mayweather, Meldrick Taylor [contiversial stopage], Hector Camacho [past his prime would have been a great match p at 130 or 135], Greg Haugen [past his best]). This might be blasphmy in boxing but I think De La Hoya was better at 135 (pre prime) than Chavez was at 140 (post prime). Therefore I would say 135 is the best weight. I would pick Chavez to win at 135 and De La Hoya to win at 140.
Catchweight of 138lbs. :smile The answer is I don't think you can have a prime De La Hoya vs a prime Chavez at a specific weight, however if I had to choose a weight where both were closest to their respective primes, I would say 135.
No I don't think De La Hoya would have domanted Edwin Rosario like Chavez did, but I think he was better at 135 than Chavez was at 140.