Who had the greater punching ability at light heavyweight? Did your pick carry their power to heavyweight or did it decrease/increase?
Moorer had a 100% KO percentage, which is impressive. Moore had over 100 KOs, which is extraordinary. I'm going with Moore.
175 lb Moorer has been turned into some mythical beast. He left the division before facing the best fighters in the division. And the division was not even as good as it had been in several other eras. He stopped Frankie Swindell and Leslie Stewart. Stewart was hurt much worse and earlier by Don Lalonde and Virgil Hill. Hill obliterated Stewart where Moore struggled with him greatly. Does anyone say Virgil Hill was among the most powerfull LHWs? No. Archie Moore is probably among the first or second best LHW Champions of all time. Archie Moore had proven power over time. Moore showed power, but you have to go with the guy who is proven, not the guy who we can only speculate on what he may have done. So, Archie Moore is the obvious choice.
Much like Edwin Valero, a 100% knockout ratio is far less impressive when it's done against an unexceptional bunch of fighters.