Timing advance Vaccum line Chrysler 318 2 bbl

Hi, DT hopefully this is the right thread.
I have a 66 charger with the 318 engine and 3 spd auto trans, 2 bbl uremco remake by Carter brothers

There is a vaccum line that I've been told is for the timing advance. My question is where does the line go to?

I cannot find any diagrams and I'm completely confounded.