The vacuum modulator is the round thing hanging off the front of the transmission. It measures about 3 inches in diameter and has a small vacuum line coming out the front which turns right and joins the plastic vacuum line from the charcoal cannister and ends up at the throttle body.
The rubber connectors, labeled 1 in my picture are the ones that need to be replaced. There are several of those and also a couple of rubber 90 degree elbow connectors that tend to rot also.