1969 Barracuda Carb Suggestion Needed

Correct! The one on the rear is a full time vacuum port. (Or there is always vacuum there.)
The on on the drivers side, front of the carb is a "timed" port which can be take. As part time. LOL
That is the one for the distributor.
This is for the Carter & Edelbrock copy carbs.
Your Mopar wants the timed vacuum port.