Factory A/C VS Non A/C Questions

[Plum6Pak]

I'm considering an aftermarket AC Heater unit. but the mfg said they are actually meant for non AC cars. He said there would be much more work to install their unit into an already AC equiped car. How much different are the non AC car firewalls VS the AC firewalls and if I decide to go non AC, can I swap the AC unit for a non AC unit relativly easy? I realize I have a B body but maybe the E body differences are going to be similar. 

[ShelbyDogg]

Do you already have the non-AC box?  The factory heater worked great in both AC and Non-AC cars. Why would you want to add an aftermarket heater. You could change the firewall holes but there is welding involved.

[Plum6Pak]

In my question it sounds like I meant aftermarket heater only, I meant factory heater. That's exactly what I want to do, ad the factory non AC heater box. I was just checking into the Classic Auto Air unit, nice setup but when I called them that's the story, won't work well in my already AC equipped car. Sounds kind of silly to me but with that, I'm just going to get the non AC unit out of another B body and throw it in. Thanks Shelbypup! By the way, anyone know how old of a non AC heater unit will fit the 70 Satellite? The one in my 66 Belvedere is in excellent shape and it sure looks the same but I haven't got it out to compare. thanks

[ShelbyDogg]

I suggest that you put an A/C box in your A/C firewall, then put in the newer compressor and custom lines.  That way you have A/C with no welding required. If you don't use the A/C, just leave the lines capped for now.

[Plum6Pak]

That's a dang good idea so I could hook it up sometime later but I was trying to get away from the huge bulky original with all the vacuum line operated gizmos and sometime down the road install an aftermarket. Guess I could install the aftermarket heater/AC box inside and do the externals later if I want. I wasn't going to weld the large hole up anyway, I am going to make a plate and gasket that will look like a AC delete plate of sorts. Thanks Shelby

[SwissCuda]

if you want I have an original A/C heater box for 350 bucks

[Plum6Pak]

Thanks for the offer but I already have my original factory AC/heater box just trying to make it simpler, I will probably end up re-habbing the unit and installing it and do as Shelbydogg suggested. Thanks!