I am putting my 67 XR7 GT 4 speed Cougar and have no idea where the vacuum hose that hose thru the firewall gose. This is a Non-AC car. Dose any know? I still have the gauge cluster out but see nothing to hook this vacuum hose to. On the diagram it looks like it is a vent hose. Dose it not hook to any thing and just terminate in the cab of the car?