Dimensions for Air Conditoner hole in Firewall

[Carolina_Mountain_Mustangs]

Member 1973_Mustang_Conv wanted the dimensions for cutting the hole in the firewall to install a factory air conditioner. I took a few pictures one from engine bay, one inside and a couple of a car without air for reference. There is an embossment where the key hole goes. If you can take the dimensions on the sketch and draw it out or print the sketch to scale, 6" reference to check print scale, it should work for the hole. I actually held the paper on the firewall with magnets and traced the opening. Just center the template in the embossed area mark, check size and cut. There is nothing that has to be accurate about the cut. I am not sure about the holes for the heater box mounting they might be different I will maybe look closer tomorrow.

There is also a picture of the "helmet" that is welded in the firewall on the outer cowl when you DO NOT have air. You will need to close off the left hand duct to the cowl also. I installed 1/4" woven wire under the cowl vents and over the entry to the heater box to keep leaves and critters out. You cannot see it and it is a pain if a dead mouse or even a nest gets inside.

The .PDF is the template with dimensions so you can verify correct size when you print.

Good luck on the install it will be a great addition to your car.

David

 

[1973_Mustang_Conv]

Member 1973_Mustang_Conv wanted the dimensions for cutting the hole in the firewall to install a factory air conditioner. I took a few pictures one from engine bay, one inside and a couple of a car without air for reference. There is an embossment where the key hole goes. If you can take the dimensions on the sketch and draw it out or print the sketch to scale, 6" reference to check print scale, it should work for the hole. I actually held the paper on the firewall with magnets and traced the opening. Just center the template in the embossed area mark, check size and cut. There is nothing that has to be accurate about the cut. I am not sure about the holes for the heater box mounting they might be different I will maybe look closer tomorrow.

There is also a picture of the "helmet" that is welded in the firewall on the outer cowl when you DO NOT have air. You will need to close off the left hand duct to the cowl also. I installed 1/4" woven wire under the cowl vents and over the entry to the heater box to keep leaves and critters out. You cannot see it and it is a pain if a dead mouse or even a nest gets inside.

The .PDF is the template with dimensions so you can verify correct size when you print.

Good luck on the install it will be a great addition to your car.

David

Thanks for the help on the printout and dimensions.

I'll double check on the parts inventory need to refurb my heater box , replace the rusty hinge parts , I thought some were available at West Coast Cougars (?) , while watching the Cougar video on refurbing the heater box. Don't know what to call the part, but I know it needs to be replaced.

 

[Omie01]

I bought the new heater box from CJ's and it actually fit pretty well, it came with all the doors and such already padded. I just had to get a new firewall seal, "from WCCC", and hook up my own vacuum dash-pots. The only mod I had to do to the new box was cut down the thickness of the heater box to squirrel cage seal about a 1/4". I think its a nicer box than the original, and it doesn't seem to be as brittle!!

 

[Carolina_Mountain_Mustangs]

Member 1973_Mustang_Conv wanted the dimensions for cutting the hole in the firewall to install a factory air conditioner. I took a few pictures one from engine bay, one inside and a couple of a car without air for reference. There is an embossment where the key hole goes. If you can take the dimensions on the sketch and draw it out or print the sketch to scale, 6" reference to check print scale, it should work for the hole. I actually held the paper on the firewall with magnets and traced the opening. Just center the template in the embossed area mark, check size and cut. There is nothing that has to be accurate about the cut. I am not sure about the holes for the heater box mounting they might be different I will maybe look closer tomorrow.

There is also a picture of the "helmet" that is welded in the firewall on the outer cowl when you DO NOT have air. You will need to close off the left hand duct to the cowl also. I installed 1/4" woven wire under the cowl vents and over the entry to the heater box to keep leaves and critters out. You cannot see it and it is a pain if a dead mouse or even a nest gets inside.

The .PDF is the template with dimensions so you can verify correct size when you print.

Good luck on the install it will be a great addition to your car.

David

Thanks for the help on the printout and dimensions.

I'll double check on the parts inventory need to refurb my heater box , replace the rusty hinge parts , I thought some were available at West Coast Cougars (?) , while watching the Cougar video on refurbing the heater box. Don't know what to call the part, but I know it needs to be replaced.

I took all the doors out of my heater box and blasted them and sprayed with paint and installed new rubber seals. The seal kit was a joke nothing like original and it was a Carpenter item.

Spray the rod and flapper down with penetrating oil. Make you a horse shoe shaped metal piece that will slip over the rod and hit against the flapper. Insert the horseshoe piece on the inside of the case on the side with the bends in the rod. Go to the end that is straight and start to tap the rod with hammer and you will have to have a long drive punch to get it out. The horse shoe tool spreads the force out so you don't crack the case. Go slow and tap don't get violent and it will come out. If the case doesn't look the best you can clean with lacquer thinner and if scratched up you can spray with clear satin paint and it will look new.

My box is all assembled and ready to go back in. You will have to cut the hole in the floor for the drain in the bottom of the heater box. I have not pulled the carpet up to look but I think it has a formed area where the hole goes if you need a picture I will get one.

I also went to heat and air con. shop yesterday and got a piece of fiberglass insulation that they use on ducts. It has one side that is dense and holds its shape. I am going to use this to replace the factory stuff that just falls off with the black plastic on it that insulates the cowl not the firewall pad. I tried to order one but nobody seems to have one. You cannot see it when done so not going to worry about it not a show car a driver. The replacement kick panel insulation is made from the same stuff like I got at the home air cond. shop.

David