I'll give it a go. Chavez Sr hit a brick wall at 147 and never accomplished much of anything. Also by that point his career not only was he well past his prime, but was extremely cut prone and his stamina lacked. Even an aging Mosley is still much quicker and stronger weltwerweight than JCC. Only was i can see Julio pulling it off would be if Shane was having an off night and Chavez could avoid getting cut. On workrate and accuracy he could earn a narrow decision. Barring that either Mosley wins a comfortable decision or stoppage on cuts.
Post EPO Mosley wasn't a whole load, and JC was no 147lbr at all. Instead, we should see how many times Sugar can get JC to return his glove-taps.