This was a universal replacement / performance type carburetor. Note the two small nipples either side of the PCV, both are ported vacuum, the right for vacuum advance, the left for EGR, note 50 & 51.. Also note the electric choke and vapor return line.
Go look at your PDF, it shows the nipple on the linkage side (#51) as FULL TIME VACUUM, not ported. Number 50 in your PDF is listed as Ported Vacuum, exactly as I said.
A simple visual also confirms the vacuum sourcing for either nipple, below the throttle shaft is full time (#51) and above the throttle shaft (#50) is ported.
