Mach 1 Vacuum Ports I found a photo of a Mach 1 with the EGR valve port plugged but the vacuum hoses still connected. There are only 3 vacuum ports on the Mach 1 upper intake manifold. Based on the above photo I think the hose routing is as marked on the photo below. I searched for a Mach 1 heater control valve but could not find one shown on the internet. I did find one for a Marauder which is electrically controlled. I assume that the hose connected to port 1 supplies the brake booster but there could be a "T" in between. Port 3 is a puzzle to me. It is attached to the cast that the IAC valve mounts to. I guess that I need to remove the IAC valve and the throttle body to determine what Port 3 is connected to. Years ago I purchased a Ford van throttle body that had a built in bypass for the IAC valve.