1966 A/C

In my 1969 Dart, I had to unbolt the AC hoses to get at the heater core since the evaporator wrapped over the heater core (evaporator further from firewall). Anyway, much easier to remove the whole box that try to separate it under the dash working blind. But you will have to vent the refrigerant so have a shop do that, or insure an EPA drone isn't watching. I put a stainless screen under the cowl vent slots in my 1964 Valiant to keep those nasty leaves out. Once they go in, they won't go out the little drain holes.