I have a 77 930 throttle plate that is different from a 76 I just worked on. The 76 has 2 tubes coming out of the front. The lowest one connects the hose from the wastegate and the smaller one above it is the vacuum line to the vacuum pod of the ignition distributor.
Now, the 77 version has a 3rd port, a larger diameter tube that is in the lower position of the previous 76 wastegate location and (I’m assuming) the wastegate line has been moved to the top position above the distributor vacuum strangely above the centerline of the throttle plate.
What is that third line for?
