Chavez cant really make 160 anymore he has been tight there for years, and even if he were to get a rematch with martinez, that would for sure be his very last fight at 160. At 168 the guys are massivly talented and pretty big, chavez would no longer be 20 lbs heavier then his opponents on fight night. I think he gets destroyed at 168, he is pretty limited and in a division full of talent he wouldnt last long in my eyes