Can I mount a vac pump like this?

I'm swapping parts from my old car into a new one. I'm having a problem mounting the vac pump. Last time it was pretty much horizontal but I'm looking at mounting it vertical this time. Any problems doing this?

I did mine like this:

I don't see why it would make a difference.

should be ok the way you mounted it.

Thanks for the replies guys. I was just a little hesitant as the Moroso diagram kept showing it horizontal. Hey Biginch, I have the same steering rack as you. How are you going to connect yours up? The engine plate looks to be in the way.