I put the Classic Auto Air kit on my 79 403 recently. I got the kit with new evap core and condenser, so everything is new under the hood. It was about $1000 from Classic Auto Air on eBay for everything. I like the fit and quality. But, I haven't charged it yet, since I still have a few other things to do to the car, so I can't say how well it works yet. I expect that it will work great. It may be a month or two before I charge it, but I'll try to remember to report back. Here's a pic:
