I did some research and found a solution. I could handle the installation, no problem. Redneck Car Airconditioning

 

25 amps at 12 volts is only 300 Watts.

I have heard that A/C systems usually require 1 to 1.5 horsepower to drive.

There are 748 Watts in a horsepower.

So 300 Watts is only .4 hp.

My guess is the electric unit won't cool worth a darn. too small.

Let somebody else be the guinea pig.

 

Mine looked about like those in the picture. Not really that bad, just nasty in contrast to the other cleanly die cut holes. Like the other firewall holes came out of the press like that then someone on the assembly line used a hole-punch tool to hand make the heater hose holes.

 

That's the difference- Most of them are flat holes. The heater hoses are holes with a lip. No one was punching heater hose holes at final assembly.

 

Anyone heard anything good about 12 V systems like this one? 12 V Electric Air Conditioning Compressor – How Can You Decide Which One is Right For You? Sean Hyland Motorsport

JeffTepper, love the car? What wheels are those?

 

OK 22GT. I've seen such plugs but didn't know how correct they were. Concours not being my thing. I found it slightly interesting that all the other holes in the firewall (of my car) were such neat and clean punch outs and then the heater hoses openings were such awful jagged and rather unplanned looking things. Curious. And why would they punch those holes on cars slated to receive AC on the production line? Did they also punch them on "heater delete" cars? Seems silly. Not that it matters at all to me, just trivial curiosity.

 

If your hose holes were ragged, somebody butchered them. When new, they were cleanly punched with raised lips to protect the hoses. They were not punched on the assembly line, the firewall was manufactured with them. All cars received the same firewall, because factory AC was rare. The AC opening was pre-punched so that it could be knocked out by line workers when the car was tagged for AC.

 

Classic Auto Air sells refurbished in dash factory air units for '67's. Check out their Mustang catalog on line.

 

I didn't "punch out" anything on my '67's firewall, nor drill any holes. The factory did punch some rather ugly holes for the original heater hoses though. These hoses are now routed (with the AC lines) neatly through where the blower motor used to be. You can use plugs to block off the old heater hose openings but they offended my eye enough that I welded them up and smoothed them out to invisibility.
Some of my AC parts came from a Cougar so my setup not be 100% correct for a '67 Mustang but in any case it was simply a matter of refurbishing and installing all the parts.
There is a punch out in the radiator support that will need to be removed. If you do an aftermarket kit you still have to remove it as the kits use the same opening. Other that that hole and how you deal with the non-AC heater hose holes in the firewall it's a complete bolt-in. Just a matter of gathering up all the parts, which I always considered part of the fun. Other folks find that sort of thing excessively frustrating or they are in a hurry. In such cases trading off being able to retain some originality in favor of the convenience of everything you need delivered to you in a box usually makes more sense.
I don't care to be 100% original. I prefer to use R134A and it requires at a minimum a better (newer) design compressor to get reasonable performance. I don't care about the underhood, I just like how all the visible dash stuff looks correct and original. Some aftermarket kits are very close though.
You can spend about the same amount of money either way, so easy way or hard way? Sort of.

 

The factory did punch some rather ugly holes for the original heater hoses though. You can use plugs to block off the old heater hose openings…

Yeah, on factory AC cars that's exactly what Ford did, insert rubber plugs in the heater hose holes.

 

Have a friend that I'm helping answer the question of
adding factory A/C on to his non A/C 67 car.
Been there, done that.
I know it would be a involved job since the factory unit
is a "integral" A/C system and not hang on like 65/66.
Well, there actually was a dealer-installed under-dash unit, too.
The firewall is different,
No, it isn't. You will need to remove the "punch out" for the coolant fittings, and drill the bracket holes at the dimples that are already there.
how about the dash?
No, it isn't.
Is the cowl different?
No, it isn't.
Is the fresh air vent on the drivers side still used?
Yes.
Any other issues?
Take the seats out. That's a 15 minute job that will save hours of contortions and pain.
I see the inside of the car more of a problem than under the hood.
I think he might be better off getting a unit from a place
like Classic Auto Air, even if he would be able to do the factory
A/C conversion rounding up the factory parts may be a challenge.
Availability of parts is actually quite good, but getting a full set from CAA will make life a lot simpler.