Full Idea
If we understand conceivability as conceivability-in-principle (by a superbeing?) then it is plausible that logical possibility of a world implies conceivability of the world, so logical possibility of a statement implies its conceivability.
Gist of Idea
Maybe logical possibility does imply conceivability - by an ideal mind
Source
David J.Chalmers (The Conscious Mind [1996], 1.2.4)
Book Reference
Chalmers,David J.: 'The Conscious Mind' [OUP 1997], p.68
A Reaction
I see nothing incoherent in the possibility that there might be aspects of existence which are utterly inconceivable to any conscious mind. Infinity might be a start, if an 'infinite' mind were impossible.