What matters more in a novel: Pacing or Length?

I'm writing an alternate-history mystery, with elements of steampunk and low fantasy. It's actually a lot less complicated than it sounds, but it all makes sense in the setting. Anyway, I'm not half-way finished yet and at 66,000 words. I understand that the word count may come down quite a bit for the final draft, but I'm worried that it's still going to be too hefty. However, when I analyze what I've written, nothing so far is useless; It either contributes to the plot or the world creation. Also, the pacing isn't slow or boring.

Sci-fi and fantasy works seem to lend themselves towards much higher word counts, however mysteries seem to be much lower. So, I guess my question is, will a higher word count hinder me even if the pacing is good?