I've got two aftermarket a/c systems, a Classic Air Perfect fit in my 55 bird, and a Vintage Air in an OT 67. They both work fine. The CA system took quite a bit of fiddling with to get the micro switches to work, and the hot water shut off valve really doesn't shut off. At higher rpm, it bypasses water, and the a/c can't overcome the heat load for a bit. A pain in traffic, not so bad at cruise.

The vintage air just works, period.

Most aftermarket systems use only interior air. Advantage is you've got dehumidified air for the defroster. Most old cars leak enough air that it doesn't get stale.

I've got a friend with an under dash a/c only in a 57 bird. It really intrudes into the interior space, and that's why I went with the CA unit in the bird. In a full size car I'd probably do an under dash a/c only unit. Lots of them out there, my favorite is the VA unit.

http://www.vintageair.com/2015%20Catalog/2015%20VintageAir%20Catalog%2050.pdf

If you want specifics, drop me a pm.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Looking for a system to install in my 55 Fairlane 12 volt , also are they reliable and easy to install ?