conceivability and possibility

it has come to my attention repeatedly the fact that many of the philosophical arguments within the philosophy of mind are based on conceivability. also many of the objections to some of the arguments are based on conceivability. Even though many would agree that as long as it is conceivable, it might be possible... right? how could it be denied that there is some sort of existence of possibilities that we just dont have access to. furthermore, the problem with possibility as opposed as conceivability is that we would have to commit to a kripkean modality , like it is not very likely to happen under a certain set of conditions but there might be a possible state of affairs under which it is possible. For example there is the zombie argument against functionalism. the problem with zombies is that they might act the same way that an active agent would, but, presumably, they wouldn't have any qualitative experience. the zombie would know what it is like to eat tofurkey, but would, nevertheless, would be able to eat it, and possibly make comments about. but the zombie would be either lying or non-consciously just trying to mimic a behavior.
this whole argument is well explored by a lot of philosophers, but it is still a conceivability argument, we cant probe it, however we can imagine a POSSIBLE world where there are zombies who are qualia absent. so it is hard to tell whether conceivability entails possibility, or possibility has different limits than conceivability.