Our 78 F-250 CS has the same set up. Does any body know what type of ac this is? I just assumed the dealer instaled it.

 

Hey doc, I should have done a search. you talked about that in another post. Your information is very helpful. I feel more confident about cutting that big hole in the firewall. The project will be well worth it. I'm still working on my chassis for my restoration project and the ac installation is way down the road for me, but I like to cover different areas so I can have a plan, when it's time to put the cab together. I had an A/C cab which was in pretty good shape. Needing both side floor pans and will need some body work the top of the cab but nothing to major. Quite a bit of surface rust on floor, but the cab mounts and cab corners were good. Then I came across a 73 F100 with an excellent body all around and couldn't pass it up, but It doesn't have A/C. So now, I think I'm going to install factory A/C in that cab. Will save me some bucks on body work.

 

That AC unit pictured above was only an example ,
IIRC, It was from a 1971.
However I saw on that like in a 78 a few years ago.
I knew I should have scored it

Presently I am still looking for a pic of a newer one like the ones you guys are describing to show you.

 

The A/C unit that you all are describing was a dealer installed unit. The controls were under the center vents, the box was behind the dash, and the ducts were routed to factory vents. There is another dealer installed box that takes the place of the glove box. This unit has a duct that goes to the left vent, and the center vent as well as right vent are incorporated in to the box. The units that you see hanging from the bottom lip of the dash board are all pretty much aftermarket.
I installed A/C in a friend of mines 36 ford coupe. There are aftermarket units that you can get that will go behind the dash and have out lets to run ducts off of. He got his box at a swap meet for 25 bucks. It had heat and air in one box, but yet it was pretty compact. I mounted the box between the dash and the fire wall on the right side of the car. I bored round holes with a hole saw through the dash and installed the vents. Then simply routed duct work from the box to the vents. Duct work and vents can be had reasonably inexpensively at A/C shops. For anyone interested in trying something like this, the rest of the instalation is pretty simple. Mount a condensor and dryer. Measure the length for the hoses, and have them made at the shop where you buy the vents and ducts. He had a clutch fan behind the radiator. I put a small electric fan in front of the radiator and wired it up to where when you turn on the A/C it sends juice to the fan. I also wired in a relay for the fan. After that, just vacume down the system, add 1 can of esther oil and 2 cans of 134A, and your good to go.
Doc