Heater box question.

[TerryD]

In the next couple weeks, I'm going to be swapping engines in the K5. While I was there, I was wanting to take the AC heater box out and put in a non-AC box.

The non-AC box I have is from a 76 pickup. What issues will I run into trying to do this swap? Will it even work at all? Thanks for any help, I'd like to clean up under the hood a little bit as we go.

 

[KansasTwister]

Nope will not work completely different. Nonac has cable driven controls, and ac has vacuum driven control if i stand correct. You can, but you need everything, including the piece of firewall as they are different sizes.

 

[toomany]

The holes in the firewall are differnt sizes IIRC. It's not that hard to make a block off plate to cover the unused area. I know the topic has been coverd before.

For some reason I'm thinking that the holes are actually the same size. The cab I have in my garage (non-ac) looks to have the same cutout as the one on my k5 (ac). I don't know. Maybe I should go out and look.

 

[Seafarer76]

In the next couple weeks, I'm going to be swapping engines in the K5. While I was there, I was wanting to take the AC heater box out and put in a non-AC box.

The non-AC box I have is from a 76 pickup. What issues will I run into trying to do this swap? Will it even work at all? Thanks for any help, I'd like to clean up under the hood a little bit as we go.

Have you thought about running a Mohave heater since you are going non-ac?

 

[pseudomike]

I have done it the other way around before non-a/c to a/c. You need all controls, vents etc. You will need to make a block off plate to cover a portion of it I had to cut a hole.

I don't think all the a/c setups were vacuum. I recall seeing a mid 70's that was not.

 

[TerryD]

Nope will not work completely different. Nonac has cable driven controls, and ac has vacuum driven control if i stand correct. You can, but you need everything, including the piece of firewall as they are different sizes.

So even if I had, say, an 84 non-ac setup, it'd still use cables?

The holes in the firewall are differnt sizes IIRC. It's not that hard to make a block off plate to cover the unused area. I know the topic has been coverd before.

For some reason I'm thinking that the holes are actually the same size. The cab I have in my garage (non-ac) looks to have the same cutout as the one on my k5 (ac). I don't know. Maybe I should go out and look.

How about between different vintages. The non-ac setup I have is from a 76 C15. The K5 is a 84.

Have you thought about running a Mohave heater since you are going non-ac?

This is going to be a streetable rig and I'd rather just have the factory stuff in and working. Now that you posted it though, I'm considering adding it in the rear of the K5 to get it warm on the inside faster on those cold winder days.

 

[pseudomike]

The box shape is the same on all vintages as is the vent work.. Just to clarify you will need both sides of the box, all vents, and all controls. The only difference in the vintages I have ever seen was in an mid '70's burb I parted. I am damn near sure that had an A/C box that was non-vacuum. Hopefully someone will chime in to verify. Personally I don't like the vacuum and it won't matter for you project either because you won't be adding it on but rather removing it. I would add the pull vented kick panels when I did it because you wont need that door on the passenger side anymore for recirculate.

I did see an odd-ball one, dealer installed A/C. Used standard no A/C box with a bunch of hokey little contraption. I'd stay as far away from that as I could.

 

[TerryD]

Sweet! I've got the non-ac still in the truck, complete and never touched. I just have to pull everything out of it and the blazer and swap them. Thanks for the info man!