I used an Alfa Romeo compressor bracket commonly used on the Spica cars. (Bosch F.I. injected cars have the A.C. compressor mounted low on the right side of the engine.) VINTAGE AIR makes a handy adapter plate that bolts onto the Alfa bracket to adapt neatly to a modern Japanese compressor. How handy! You can see in the engine compartment photo that I opted to use a "modern" multi-groove serpentine belt drive. In order to do that I added a 6-groove pulley off a junkyard BMW, welding it to the crankshaft pulley. I also used a "modern" spring-loaded idler sourced from some Japanese car (have fun at the junkyard!), and a 12" pancake radiator fan from the auto parts store. I already mentioned that I obtained a 24"x 13" condenser from the junkyard (make sure it's a post-1995 so it has R134a fittings). V-A strongly recommends you use the largest condenser that will fit in the car, and that's what I did, and I installed another 12" pancake fan on the front of it. You can also buy condensers and fans from them and other places - - read what V-A says in their helpful catalog.
Getting back to the compressor, you can see it overhangs the original battery box, so undoubtedly in every Alfa installation the battery will have to go in the trunk. Amazingly Alfa provided a recessed battery box in the trunk floor of all Alfettas which was extremely handy. On my car I could also see evidence underneath where the battery cable was to run, and so I was able to have a neat and safe cable insulation outside of the car.
My final photo shows the V-A receiver drier installed on the firewall behind the Alfa cold air box, and a black gizmo mounted on the rear of that cold air box. That is the servo heater valve (from V-A, of course). These parts can be installed about anywhere you desire, inside the engine compartment or under the dash.
Yes, there's a bunch of parts placements, clearance concerns, wiring and "hosing" to do. I spent many hours figuring out how to make it all work, but WORK IT DOES! To answer a big question, all this cost around $2200.
I know these few photos and my description leave out a lot of details, which would vary depending on which Alfa you own. The VINTAGE AIR catalog has a real good guide for installing A.C., and I would be glad to answer any questions one might have about the installation. Since I don't regularly monitor the ALFABB, contact me at firstname.lastname@example.org
then I'll probably post replies on the Forum, too.