i havent personally done it but i have seen a few cars with it they used the 455 brackets and compressor
i'd imagine the hardest part would be getting that pass valve cover under the ac box... it's tight, but i think you can do it... i pulled my AC box out, as the rest of the system was missing anyway, pulled the heat out with it... kinda wish i didn't now, but oh well, to late it'll keep me from driving it in the winter, and spinnin out on ice/cold pavement.
Mine HAD ac but I think it can't be done with the stock ac box? I had to cut mine and move the heater core . Then fab a cover to fill the hole.
Hmmm. Well I'm not above any fabrication work (in fact that's my favorite part of any build) but I will not eliminate the heat. If nothing else, the defrost is nice if you get caught in a rain storm some cool spring night. Guess I'll cross this bridge when I come to it.
Have you considered an aftermarket unit that would fit inside,behind the glovebox.Vintage Air,Southern Air and others have some nice systems out there.Most of these kits will give you a flat firewall and really clean an engine bay.They also use smaller compressors.I've seen and original Buick bracket modified by welding the Sandem(spell?) compressor's top part of an universal,readily available bracket,and it looked like a factory piece.I've decided to go that route with my '79,whenever that times comes.
That will be another option to look into. It will be a long while before the 455 even goes in; I'm focusing on the body and interior first. In fact, I haven't even touched the car since dragging it home, but I hope to get a lot done over holiday shut down!
The only other thing, besides the 75-76 valve cover was to use a '78 compressor line or have a line made to hook the long compressor to the later style system on the Regal. I also put some of that stick on insulation on the fiberglass A/C box on the firewall around the said valve cover as I was putting it together, incase is was too warm or too close. I just took the two AC lines(manifolds) new and old, and had the ends swapped at an industrial hose place. Seems like it was $20 or $40 bucks. Both of my hoses, or well the hose off of the G-body was for a V-8 car, so I had plenty of length, the V-6 may be a little shorter. I was working with what I had.
