I would lean towards Kovalev but I wouldn't be confident about it. Moorer had a glossy record at 175 but faced rather limited opposition. I'm not really sure as to how exactly rate Moorer at 175. Obviously he was a powerful guy and a big LHW, he had a nice southpaw jab and could put punches together. On the other hand, his competition was weak and I was rather underwhelmed with his performance against Leslie Stewart, who was probably the best guy he faced at the division.
I was more confident in a Kov win back when I had more confidence in his chin. At this point, I dunno. Kov was overall better at 175, but I won't pretend like there's not a legit chance that Moorer blasts him out. My gut tells me that Kov is controlling the fight for a while, then gets caught with some bombs he can't recover from. Moorer, if nothing else, was a great finisher once he got a guy going. Moorer by stoppage.