6884rocket

I am in the process of converting my '68 442 from a non-AC Car to AC car with the OE Harrison/Frigidaire system. Yes, I do understand this is regarded as a form of sacrilegious violation by many but I'm in FL with a spouse, child, and an octogenarian parent thus unfortunately, AC is a necessity 99.98% of the year.

That being said my vehicle is factory heater equipped. I need the conversion to appear perfect to a judges eye as I am cursed with horrible OCD (which is probably great for restoration of cars!). Would anyone know if the heater fan section of firewall/cowl is the same as the AC vehicles or do I need to adapt, replace the section, or (hopefully not) the entire firewall.

My thanks to all the very smart pros who may be of assistance by providing their advice and guidance.

Dave

MDchanic

The firewall is different.

The air pass-through hole is vertical for A/C, horizontal for heat-only.

I've done it (for a different Division), and it wasn't pretty, but it wasn't visible when it was all assembled.

- Eric

6884rocket

Eric

Thanks for the information. I was fairly certain that the heater and non-AC were different. I suppose the best option is the AMD '68 - '72 A-Body replacement firewall for AC vehicles which looks chock full of posterior pain in every aspect. I have been told that cutting the AC-blower box section of firewall from an AC vehicle and then cutting the similar section from my car and welding the other portion in can be done but I am uncertain of a perfect outcome as the metal work has to be good enough to look like it was never done.

V/r
Dave

MDchanic

You're nuts.

If you cut out the vertical hole in your firewall, and patch the horizontal parts you no longer need with sheet metal, nobody will ever know.

If you want to replace your whole firewall, or try to weld a section into it invisibly, then have fun!

- Eric

6884rocket

Eric

You're right, I agree with you that the firewall in the carl should be changed. The way I'm envisioning it the applicable hole(s) should be closed with the same gauge steel and the correct hole(s) cut where they should be and the whole section refinished (grind, sand, prep, paint) to appear as it was built as an AC car. This would also eliminate any potential fit and connection issues on the firewall.

The real tricks are to locate an AC car firewall to copy and find the skill in a metal worker to execute it all perfectly. Most unfun.

Dave

MDchanic

Alright, this is getting out of hand.

I never said that. I said the opposite.



You are getting way over the top here.

There is no mystery to this, and changing the holes in the firewall is really no big deal, and is the least difficult and annoying part of installing factory A/C.


Look:




Here is a guy who wanted to do just the opposite of what you are doing:


If you look at this picture, he has a firewall punched for A/C, with the heat-only parts placed in their proper locations. This shows you where you will have to cut:



If you look here, you can see the two holes both cut at the same time.
With the residual outline from the A/C equipment, you can see that the piece of sheetmetal that you need to screw, rivet, braze, or weld on will be almost completely covered by the A/C box, except for one corner where the hoses pass through, which will be completely obscured by the hoses, which is to say that the modification will be completely invisible:



Here is a picture with the fender in place. Notice that that spot where the hoses pass through is under the fender mount bolt, so you can't see it at all:




Plus, as an added bonus, all bolt hole locations are pre-located by dimples, so you don't actually need to measure or figure anything - just hold the A/C parts up to the firewall, line up the screws with their dimples, mark the dimples, and drill.


Don't overcomplicate this.


- Eric

6884rocket

Eric

Roger. Tracking all. "Changed" meant "altered" sorry for failing to articulate thoughts clearly. Guess I seem to over complicate things due to real bad OCD. The service made it worse over the course of 2.3 decades.

Thanks much for all of the photographs and clarifying guidance. It makes everything in the process exponentially more understandable. I had no idea that the stamped steel was dimpled for drilling locations as its been many, many, years since I last had a hard look at and personally dismantled AC/Heat/Fan assembly's on an A-Body (1980's).

With everything you have shown it looks pretty darn straightforward. I'm going to generate hard copies if the photographs and your guidance for the shop I'm going to have do the job (no time at all to do it myself like back in the good old single me, myself, and I era....what great times) who are pretty good as I saw the same conversion job they did on a '67 Firebird ragtop that looked great.

Owe you beer or favorite beverage for the help...

Cheers,
Dave

MDchanic

No worries. That's the problem with the interwebs: What gets transmitted isn't always what gets received.
As the last frame of a "B.C." comic that I read many years ago said, "Language is such a dumb way to communicate."



Oh. You meant actual OCD. People use the term all the time, but don't mean it.
Sorry. That can be a b__ch. Not always a bad thing when restoring cars, though.
Guess it could be helpful in the service, though I suspect the men under you might disagree.
For the sake of thousands, I hope you weren't a First Sergeant.

One thing I can say, though, is that you'll find it is an asset on this board, where we tend to prize accuracy above all else, and do our best to prevent "truth decay," as Joe like to say.



You're welcome. That's why we're all here.



It seemed that way to me when I did it back in 1981, but, of course, I was younger then...



Thanks! I like mine dark and bitter -- like my women.


- Eric

6884rocket

Roger. You're right about language! Posts and e-mail are misinterpreted regularly which is why I use both only when I have to. Never had a shrink tell me I have it but I know I do.

Worse...commissioned officer (Major). Some were far, far, far, worse than me though. We called them Colonels and General officers!

Don't depress me...1981 seems like it was yesterday. Also used to own a '81 Turbo TA which was my favorite non-Olds (right before I upgraded to Olds) which I wish I still had even though it was ridiculously slow. Everything else about it was awesome.

Well anyway thanks again and I'll make good on the drinks if we ever run into each other at a meet. Haven't been to anything since the GM Nats at Carlyle in '13. If there is ever info you need hit me up and I'll help out any way I can.

Dave

oldsconv

Just a couple thoughts. I am a perfectionist also, but to do an exact factory conversion requires a lot of AC specific parts like vents, controls, kick panels, brackets and on and on. You will basically need a donor parts car that has AC to get all the pieces.

I know it is not factory correct, but Vintage Air and others make a unit that mounts under dash and functions well.

Up to you, but just wanted to mention it as a lot of the factory AC parts you need are not reproduced.

6884rocket

Thanks but I researched the aftermarket systems and elected to install the OE system as it cools more efficiently and was engineered for the vehicle. I initially wanted a parts car but forty-eight year old parts that have not been tested or refurbished such as compressors, condensers, POA valves etc are too large risk to install and hope they function correctly. Parts in good condition or restored are not all that difficult to locate actually. It is a matter of gradual purchase as some of them are quite costly for this model year car.

My recommendation is that an AC car should be restored as it is always beneficial for long term usage of the car. There are those who disagree and maintain that musclecars should never have AC in order to remain "pure" to the spirit and intent of the cars. Now if you own a car to race only it is better to not have the additional weight and engine compartment clutter in the vehicle. Age old theories around since the musclecar was born.