A/C- non A/C conversion??

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mopowers

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I'm in the process of taking all the AC components out of my 68 Dart. If I get a non-A/C box, will it bolt up to the firewall. I realize the firewalls are a bit different. I mainly just want to get rid of the vents.

Is there are easy way of making this conversion??? Or should I just cap the A/C lines on the firewall, remove the vents inside, and block off the opening where the core is and call it good?
 
The mounting hole is smaller for the non ac heater box. It would require modifying the firewall. Example below as I did just the opposite with mine. You can see where I have it drawn out to cut for the ac.
IMG_0018.jpg
 
Yeah, understand that. I was planning on making a cover plate, or just modifying the A/C box to only be a functional heater box. Has this been done???
 
I'm sure it has, the plate sounds like a great idea, few self tappers and your golden!
 
Other than the bigger hole in the firewall (which I plan to make a cover for, would a heater box from a non-A/C car work it it's place? The car is a 68 Dart if that matters.
 
Does anyone know if I could just use the A/C heater box and ditch the A/C box. It's my understanding that they are only connected to one another by a single bolt?

Or would it be easier to just use a non- A/C heater box?
 
Im doing this same thing right now. My heater box (71) is connected with one bolt but the fan is on the wrong half. I looked and looked but it was way to much work to make the A/C box work like I wanted it to. I picked up a non A/C box and making that to work.
 
I am converting mine right now, I welded up all the holes then took the non ac box apart. I used just the half of the box that is against the firewall to make the holes i needed to drill. Drilled everything out, once completed you wont ever know my car had ac.

The box I am using is an earlier style but that is only because I like the style that has the trim ring better then the later style that just has studs sticking out
 
So, do the A/C and non-A/C heater boxes have different mounting holes? How hard is the conversion??? I'm just trying to get rid of the A/C stuff.
 
Yeah the mounting holes are completely different, the ac hole is twice the size the motor holes actually vary a little from year to year for both ac and non ac. Non ac boxes mount with a j hook into the fresh air hole in the cowl plus with studs coming out from the blower motor area. Depending on the year there can also be a brace welded to the bottom of the cowl. Some years also have a small plate that mounts over the heater hoses too.

If your going to do the swap look for an early style box that has the metal trim ring that mounts on the engine side of the firewall. To me this is a nicer look and mounts a little better plus if your holes are a little off then the trim ring will cover that.

Its really not that hard, i welded all the wholes shut and then just held up the empty box inside the car to mark my new holes. It was tempting after I welded everything just to skip it all together and have a smooth firewall but my welding isn't perfect and I didn't want to spend the rest of my life doing body work in that area. Plus I knew the first time i got stuck in the rain I would wish i had a blower for defrost.

Look at this thread http://www.bigblockdart.com/forum/showthread.php?2092-How-To-for-Heaterbox-Motor-Modification

I used this thread to also put in a smaller motor so if i go big block down the road i'm not going to run into and issues with the motor being out to far. You can recess the motor and also there is a model of motor that is a lot smaller. With both of those mods the motor is almost flush with the trim ring.
 
Thanks for the help. I'm thinking it may be easier to just remove the under dash vents and use the existing setup for the heater/defrost. I have a new heater core for it anyway. Do I need the vacuum pod on the inner fender in this instance?
 
Completely different...the whole firewall stamping is different, absolutely nothing interchanges.

Why not just keep the A/C?
 
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