[GrannyGrump]

I'm hoping for some opinions. I have searched, but it was difficult to devise search parameters for this question.

Is it beyond the pale to use both endash and emdash in the same book?

I would like to use the spaced endash for the usual paranthetical phrases, as in:
His thoughts were confused – he had been drinking – and he did not answer.

But to me, endash does not look right when used for an interrupted word. For example, "I would like to kn–" looks odd to me, and "I would like to kn—" just looks better.

There is discussion about use of these dashes in many web articles and blogs, but none that I found discuss the possibility of using both within the same text. Is this permissable, or not?

I'm looking forward to some feedback, or links – if you have some to offer.

EDIT: I'm looking forward to some feedback – or links, if you have some to offer. (We'll just pretend I didn't mess up the placement of the dash, ok?)