Yes, two go to the thermactor system which you don't have and one goes to the EGR valve. If you trace the lines through you'll see a group of three vacuum control solenoids. The big one on top by itself is EGR and the two below it are for the thermactor.
There is a line that goes from your gasoline vapor canister to your intake. I wasn't sure if you were still using that. That's a pretty big line. 3/16"-1/4" I think.
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351W 89 Mustang GT Convertible