I'm putting A/C in an original non-A/C 73 Century. It had a cowl vent with a cable actuated door; this fed the center vents in the dash. The A/C setup has a duct from the A/C plenum for this vent, and no provision to do anything with that cowl vent that I can see. Anybody with one of these cars with factory A/C who can tell me if there's anything up there in that cowl vent area? I think I'm going to make a sheet metal cover for the hole and RTV it in place.