1968 Mustang A/C

RU concerned about period correct?

No, Personally, I think the ones they produce for '65-66 don't look good and are to small. I'm thinking about putting this in my car (the 400 series)from this url. Custom Aftermarket A/C Systems & Replacement Parts for Hot Rod, Classic, & Vintage Cars/Trucks - Underdash A/C Systems

I researched this a couple of years ago. The above url offered the largest one for under-dash unit (most openings on the unit). Another company 'classic auto air' had a decent unit but stopped making it because it was not selling. Then went with the one I mentioned above for '65-66's. Here is another company http://www.vintageair.com/2014catalog/Pages%20from%202014%20VintageAir%20Cat%20rev%208-15%2033.pdf has a semi decent looking one. I guess it also depends if you want cold air in your face or just cold air. I have a '67 fastback, Lime gold, C4, 289 A-code, 2+2

AC systems are not cheap, cheapest route may be the all in one hang under dash unit as mentioned above with the evaporator, controls, outlets, etc. built into one unit. That unit can be pretty much universal as the condenser (mounts in front of rad.) and receiver drier can be. The motor specific part is going to be the compressor mount/ compressor and pulleys as they must line up. Running the refrigerant lines and electrical can be fairly universal also.
I would still use the Sanden style compressor (need mount mentioned above) for it's compact size, efficiency and universal replacement and uses R134 freon. The original box style one is heavy, inefficient and harder to find as well as not necessarily set up for R134 as they were R12 units, the rubber, etc. is not compatable with both types of freon and R12 is rediculous $ and hard to find.

As far as vents you can still find them on fleabay, etc. or use universal ones made to fit mustangs or just use the ones built onto the hang under unit.

I plan to install AC in my '67 but will use most of the CAA kit, I've already colllected parts like the drivers side controls, center and passenger vents as I like the stock look inside and the required crank pulley all original parts. The engine parts will be the Sanden compressor/parts from CAA.
1967 or 1968 Mustang-Cougar Air Conditioning System | 67 or 68 Ford Mustang Mercury Cougar AC

Jon

Cheep is not always cheep. Make sure it will work well enought to enjoy, and will not break. I had a aftermarket air in a small BMW. It worked OK. When your sweating the extra few hundred will seem like money poorly spent. IMHO.