If you try that it only pushes the main text block down. I think the best you could do is paste carriage returns into the header fields—but that’s not a good way in my opinion.
Honestly, as it sounds like you’re sending this directly to a printer, we don’t recommend using Scrivener’s PDF generator for that kind of thing. It’s aimed more at proofing quality output. You’d be better off exporting to a word processor or desktop publishing tool and finishing off the final layout in an environment dedicated toward that task. Not only will you have better control over the layout of the page for stuff like this, but the typography, text layout and other detailing will be superior.