Meant to mention I need defrost as much as heat esp. when my overworked panting dog(s) steam the windows up, you might need to tell your wife to hold her breath on cold days 😂. Looks like your windshield defrost ducts are MIA, they have become a bit of unicorn for replacement. Legroom is another key factor, those Hupp-like ones do consume passenger space. The factory heater for ‘65 was centered under the dash over the tranny hump.