Hi guys, I have am retrofitting a 1983/1984 era emissions setup on a 305 roller motor in a 1983 Firebird. I have all of the vac lines for the carb and emissions system figured out using diagrams and the factory service manual, except for a couple things. The factory emissions diagram shows that the MAP sensor hooks up to a port on the rear of the carb. Unfortunately the diagram is an overhead shot, and the carb has 2 rear small ports -- 1 is on the base of the carb angled toward the pass side, 1 is on the airhorn up top in between the secondary butterflies. Which port is for the MAP sensor? What goes to the other port on a 1983? Thanks!

 

The MAP goes to the one in the base, toward the pass side.

Nothing goes to the one on the air horn; plug it.