I have the factory vents, so I will use them. One downside is that you have to block off the factory fresh air hole on the passenger side of lower cowl. Because of space considerations, I ordered the Vintage Air Super Gen 2, heat, cool, and defrost. I am going to reinstall the original defrost ducts under the dash at the base of the windshield and plumb them to the new unit. The factory flip up vents on the top of the dash will now only be used for AC. I originally ordered a 22" wide condenser because that is what my radiator is. Because of the way the condenser is constructed, I found that this was too narrow. I have exchanged it for a 24" X 14" piece. I am going to run the heater hoses through the fire wall near the passenger side inner fender panel. Again, for space considerations, the A.C. lines will have to go out through the inner fender at the suspension adjustment hole, and through the cowl under the front fender.