Distributor Vacuum Advance?

Hey guys! Have a really basic noob question so this shouldn't be too hard!

I have a 69 440HP, and the vacuum advance on the distributor hasn't been hooked up since we installed the engine. It runs fine, it has the purple cam so idle is a bit rough.

My question is, do I need to hook this up? It doesn't seem to run any different if I plug the vacuum advance port on the dizzy. Its currently not capped, which probably isn't good, but I'm debating to hook it up or not.

I have a holley 4bbl, I'm guessing it has the timed vac port on the passengers side by the primary fuel bowl.

I've done some research and the only thing I found is that you dont need vacuum advance if the mechanical advance is dialed in right? Any help is appreciated thanks guys!