HVAC Box Removed and Modified to Keep Heat

[New2chevy]

Yeah it's been a PITA.

[New2chevy]

Don't get me wrong....I used tin snips both to cut and smack parts of the box off, and then I used a frickin' awesome air grinder to finish it all up. I also used my construction bar to "ease" the damn thing out of the firewall and onto the passenger side floor. I couldn't figure out what the frick was holding it in there after I got all the screws out. Loosening a few of those screws really sucked with my engine in the car. The dipstick tube was one problem. I broke the plastic top of it.

Lol guess im a hillbilly, I just took a hammer to mine then made it flush and stuck a delete panel over it... I will say it cleans the bay up so much.

[New2chevy]

Question: don't some of those little screws that hold it all together poke through toward the front of the thing and get in the way of the AC delete plate?

[New2chevy]

Thanks Geoffrey

[New2chevy]

The fun continues.

Got my AC delete plate today. There are only 5 holes drilled in it. There are, at least, 9 holes to use to mount the thing to the firewall. Anyway, I am going to utilize 8 or 9 holes to mount mine up.

There are a few other challenges, too, such as some of the holes in the original box are too large for the factory screws to even bite into. Second, one of the screws that holds the heater core cover on goes in from the backside and then pokes out and prevents the AC delete plate from sitting flush against the original box. Plus, the AC delete plate isn't designed for those who want to keep their heater and blower fan, hence no hole for the heater core hard lines.

It is a little confusing, at first, but things start to come together, once you think about it and look at it for a while.

Here are some pics:

Took the heater core out and traced where I need to cut the hole, on the AC delete plate, for the hose nipple pipes.

HVAC43.jpg

The next several pics show the holes that I will be using, from the bottom right then to the left and up around the top of the box. Two of the holes are actually little "towers" on the backside of the box, in which I can screw in the original screws. The large holes (like the ones directly below) I will have to use bolts and nuts. Kind of a pain, but oh well. The pics are looking at the back of the box toward the inside of the firewall, as if it were installed.

Holes 1, 2 and 3
HVAC42.jpg

Holes 4 and 5 (the tower things in which the original screws will go into)-the top large hole is where I broke the corner off the original box and didn't realize it until I got my delete plate. I could use this hole to, at least, secure the AC delete plate against the firewall at this corner.
HVAC41.jpg

Holes 6 and 7
HVAC40.jpg

Hole 8
HVAC39.jpg

Here is another pic that is shows a bit more to the left than the pic above, and this shows another larger hole that would be hard to sandwhich the whole box and AC delete plate between the firewall because the duct fits behind this and it would be near impossible to get back in there and hold a nut onto a bolt that goes through the firewall. I will use sealant in the areas that I cannot use bolts.
HVAC38.jpg

Here's where one of the little screws that holds the heater core cover on tightly pokes through the box toward the AC delete plate. I'll probably countersink a screw in there and go the opposite way. I want a good seal here.
HVAC44.jpg

I'll still have to drill holes on the AC delete plate, to make this work. As I said, the fun does, indeed, continue.

[Mystery Bird]

With the skills you're showing in this thread I'm surprised you didn't make your own delete plate.

[New2chevy]

Nice ride man.

Yeah I just didn't feel like cutting one.

With the skills you're showing in this thread I'm surprised you didn't make your own delete plate.

[New2chevy]

I've finally got the "HVAC" box to where I just need to drill the final holes for mounting, glue the old gasket against the aluminum AC delete cover to seal it against the firewall on the inside of the car, and put the rest of the box totally together with the little screws (the duct above the blower fan, the heater core cover, the heater core itself, etc).

This project has been like a "brain teaser" puzzle, for me. If you undertake the same project, you'll see what I mean, for sure.

Here is the tunnel for the airflow. This also shows how I cut too far back on the rounded blower fan housing.
HVAC47.jpg

To secure the heater core holder/enclosure, I had to get two countersinking flathead screws then drill a small countersink into the front face of the black panel then secure the enclosure to the panel using locking nuts. One screw fit in just like factory, to secure it in another spot. The other part is a little hook that is molded into the panel and secures this part to the panel. Here's one side with the screw and nut below.
HVAC53.jpg

Here's the other side.
HVAC54.jpg

The heater core enclosure had a gap between the foamy gasket and the rest of the panel (it was bowed). I used Devcon "Weld It" glue here and then clamped the pieces together for an hour. Worked like a charm.
HVAC55.jpg

Good stuff!
HVAC56.jpg

I used RTV all around the entire edge of the modified panel then stuck the aluminum cover on it so it was aligned how I wanted it, then I clamped the sucker down and left it overnight.
HVAC51.jpg

Here it is, just missing some of the mounting holes, blower fan, the duct that goes above the blower fan, the heater core, and the cover that goes over the heater core enclosure. I probably have to do more cutting on the hole for the heater core hard lines I used a 1 1/4" hole saw bit here. I'll need to finish it up with a dremel, if the hard lines won't go through here. One nice thing is that there is a foam grommet that seals around the hard lines. Not sure how I am going to use the grommet now, but I'll figure something out.
HVAC46.jpg

[New2chevy]

Here it is. Just have to drill the mounting holes.

Whoever does this same project....plan for lots of work.

I hope my thread helps out those who tackle this job.

HVAC59.jpg

HVAC60.jpg

HVAC61.jpg

[Soxxpuppet]

definitely one of the best written up and descriptive threads on this. Goodjob!