here is a slight overview of what i did and how i blazed the trail for anyone else with a heater box and ac car.
the heater core section is only held by the sky hook inside the vend door on the pass side and by one bolt that joins it to the main box that has the ac unit. the main box is the one that is bolted to the firewall with 4 bolts one on either side of the blower motor , one under the overhand where the wiper motor sits and one behind the dist. cap. the heater core is help in the box with 4 bolts, and that box is held together with the clips that everhone talks about. now the larger 3/4 of the box holds the blower motor and runs left to the ac unit. its all one box. the heater core box sits on top of the 3/4 box and does not even contact the firewall. the seal over the vent door is the same, and it has a foam seat shere it joints the blower motor housing. that is all. there are vac lines that you mark and remove. you need to remove the glove box, the ash tray and the radio first. then no problem
2nd. the ac unit
this box is held by the 4 screws. do not remove the blower motor it is attached to the box and sits in the firewall with a rubber circle around it and it comes out with the box too. once the core is out the 3/4 box comes out easier. its heavy with the ac unit and the blower motor, it has a few elect plugs that you need to mark as you remove and the rest of the vac lines. its has nothing at all to do with how you remove the one for just a heater/non ac car. but it wasn't bad. just a few more parts and doors and vac units. getting it back is will be the rest of the store, i'll give you a write up when that happens after i paint the firewall. the ac drain is a copper stub that goes through the firewall, place a hose on it before you put it back and then tril off the excess afterwards and seal around it. should'nt be a problem. the unit has a 1/4 inch piece of insl, looks like hood insulation that sets between box and firewall. no cardboard. mine came out in tact.
