50-50 for me, I really like that one. Would be good sensible matchmaking which we don't see enough of in boxing today. Lopez deserves a Judah like name at least.
I'd pick Zab by decision. Super Judah is quick and ellusive, I think he'll opt to move and potshot/short combos for most of the fight. Lopez's chin is solid and he has great stamina so I wouldn't bet on Zab knocking him out. The pressure could get to him though and Lopez overwhelms him. One of the many great fights to make at 140 imo.
Judah looked fantastic in his last fight, good movement both offensively and defensively. He was definitely in condition too, I say he knocks Lopez out around the eight on ninth round if they fight.
You should check out his stoppage of Ortiz, who's like a bigger, younger, kinda Mexican Judah. It was just yesterday.