Should be pretty simple. What vacuum connections are you unclear about? It might be in a 63 Chassis Manual.
When you said vacuum hose diagram, I thought you meant engine. For the HVAC, you need the chassis manual. https://www.ebay.com/itm/1963-Buick...334305?hash=item56e08a1961:g:i3QAAOSwqeBfJasf https://www.ebay.com/sch/i.html?_fr...kw=1963+buick+riviera+chassis+manual&_sacat=0
It's not at all simple, it take some studying of the manual while looking at the vacuum transfer station is what I call it. Send me a pm with phone or email and i'll send a few pics of pages that might help. Gary
Aaron, I did and tried sending it twice. It says i left so... PM your email again as verification. I will try to send the pages one page per email and see if that works. Gary