If it is N/A then the first vacuum line (the one closest to the front of the car) should go to the little green plastic vacuum deal on the side of the head (I don't know it's exact function, but has something to do with the vacuum governer and the control pressure regulator, also there are a bunch of little vacuum lines down there to replace). The second one (middle nippple) should run to the flame trap. And the third (closest to the firewall) should run to a check valve and then run to the firewall (pretty sure it creates the vacuum for the a/c shutters). There are also two vacuum lines that run from the back of the throttle body to the charcoal canister in front of the driver's side wheel well.

On my '81 there is a vacuum diagram on the bottom side of the hood... It was very helpful when replacing the vacuum lines that run to and from the control pressure regulator.

Good Luck.
Adam.