Hi Gregor, maybe I misunderstand, but if you bet 70-80, and he moves all-in for 50-60 more, does that mean that you are going to lay it down? Wouldn't you still call it anyways due to pot odds. And if so then it doesn't matter if he disguises the king or not. I never play at these levels, so could be (and probably am) way off. Also what hands is he going to call a 60 (like palman suggested) or 70-80 bet, that he's not going to call all-in with. If you make the all-in bet, he only has to call it half as often as the 60 bet for it to be more profitable. Just my thoughts.
Brett