Need help installing factory A/C in a non-factory A/C 67-72 Truck

[kna4977]

There has to be someone else out there that has had the same idea as me, installing factory air in a non factory air 67-72 Chevy or GMC truck. With that being said, I would appreciate any tips that you can give me, that would make this installation easier and more successful. I am especially worried about drilling holes in my dash for the vents. What is the best way to do this? Also, what is the best way to cut out the firewall, and what is required to install the flapper that closes off or lets in outside air? What is the best way to wire in the factory air unit into the existing wiring harness, or is it better to use the wiring harness from the factory air truck? I'm sure I'll have more questions, and there are probably questions that I don't even know to ask at this point as I just have all the components, and have not begun the installation yet. I just want to know what I'm in for before I do it.

[Tweeder]

I don't know if you've already seen these options or not, but there are complete AC kits available for non-AC trucks. The ones I've seen, heard, and read about are:

www.vintageair.com
www.oldair.com
www.classicparts.com formerly known as www.chevyduty.com

From the description of these kits, it reads as though they give you everything you'll need to put AC into your rig. They're around a $1000 when its all said and done though. The only thing that sorta has me hesitant is when they say "designed to fit below/above (I don't remember which) your factory heater controls".... something along those lines. I would prefer to have a system that is as close to factory as possible, as far as the controls, the doors, the vents..... everything.

[drink2mny]

I moved ya off the parts board, so you would get a better feedback..

[kna4977]

Hey, thanks for putting me in the right place super moderator I have seen those kits, and noticed how un-original they looked, which is why I went with a factory system.

[Botietruck]

PM sent

[pumpkin]

I did this to my pick up. I cut the firewall out of the doaner truck, and welded it into mine. For the rest, I found that there was dimples where ever holes need to be drilled. For the vents I just used a hole saw. I still have the A/C dash, cause at first I was going to just weld it in, but decided to save it, just incase I wanted to get rid of the cd player. After the fabricating was done, it was just a matter of bolting it all together. I used all the parts and wiring out of the doaner truck.

[Huck]

I would remove the hood, pass inner fender, pass hood hinge, glove box door and glove box. Next would be the removal of the old non A/C dash. With it out, it makes swapping out things much easier. Next would be to remove the outer and inner heater box. Then put your A/C overlay in place and mark your firewall to cut out the additional hole for the A/c system. Next would be to install the A/C inner and outer boxes. Do all this before you think about installing the A/C dash. You should be able to get most of this done in one day--you need to order new Defrost, heater under dash waffle hose kit. Leave the compressor, associated hoses and grill stuff for last as that is pretty easy. This is pretty much the reverse order of removal~~.

[kna4977]

Originally Posted by pumpkin

I did this to my pick up. I cut the firewall out of the doaner truck, and welded it into mine. For the rest, I found that there was dimples where ever holes need to be drilled. For the vents I just used a hole saw. I still have the A/C dash, cause at first I was going to just weld it in, but decided to save it, just incase I wanted to get rid of the cd player. After the fabricating was done, it was just a matter of bolting it all together. I used all the parts and wiring out of the doaner truck.

Did you use 2 different sizes of hole saws as the factory holes are not completely round? If no, how did you make the holes, so that the holes were not larger than the vent?

[kna4977]

What's the best way to cut out the firewall?

[68350]

I did it the same exact way pumpkin did, as far as elongating the holes, I used a dremel tool for that and the finishing of the other center vent cut-out, too. I just used a big sheet of paper, then transfered it to cardboard for the holes on the firewall, though. I just modified mine to the a/c holes. I had thought about cutting the firewall out of my a/c parts cab and doing it that way, but the way i did it seemed easier in the end. I also just switched harnesses from non-a/c to a/c. If you have an a/c cab for reference, use it for all the measurements and everything as it will help a lot. I think that is about everything I can help with.

[68350]

If you are cutting the firewall out and switching it, I would use a die grinder(air tool) for most of the cut, following it with a dremel as the dremel seems to be easier to get stuff more exact.

[kna4977]

I've got an A/C dash, but I would have to paint it, and then cut mine out and weld that one in. It seems easier to me to cut the holes by using templates from the holes in the A/C dash. Does anyone remeber the size hole saw they used for the majority of the 2 side dash vents?

[kna4977]

Originally Posted by 68350

I did it the same exact way pumpkin did, as far as elongating the holes, I used a dremel tool for that and the finishing of the other center vent cut-out, too. I just used a big sheet of paper, then transfered it to cardboard for the holes on the firewall, though. I just modified mine to the a/c holes. I had thought about cutting the firewall out of my a/c parts cab and doing it that way, but the way i did it seemed easier in the end. I also just switched harnesses from non-a/c to a/c. If you have an a/c cab for reference, use it for all the measurements and everything as it will help a lot. I think that is about everything I can help with.

I've got the cardboard template, so I'm not going to weld in the portion from the A/C truck. How did you cut yours out?

[68350]

I used 3 1/2 inch hole saw, but then i finished them up with my dremel. As far as the firewall, I will be using a die grinder for any cutting, and finishing it up with the dremel, which u can buy metal disks for at wal-mart. anything else, just ask.

[kna4977]

I've got both the service manual and the factory assembly manual, but cannot find anything about the flapper. Do you have to cut out for that???

[John Fabris]

Nothing to cut out, you only have to drill two holes, one on the firewall side, one on the back side of the firewall (access from glovebox)

IF you look closely, you will see the dimples which are where you would need to drill...