Non-AC Heater Box Gaskets/Seals

[misterjason]

Hi everyone, I'm looking to rebuild the heater box in my 71 non-AC Mustang. I can't seem to find a gasket/seal kit available. I am finding them for the AC cars, though. Will the AC kit work or is there another alternative? Thank you.

 

[bdennis]

I could not find any repro seal kits for the non AC heater box.
I ended up driling out the rivets that hold the metal backing on, then replaced the core and made my own seals.
I went to the local hardware store and bought some high density foam and made my own gaskets.
Here is a link to a few pictures. https://72mach1mustang.blogspot.com/2022/12/heater-box-and-decals.html
Unfortunately I did not take any pictures of the gaskets I made or the rebuilt box.

In order to replace the now drilled out rivets, I just used small screws with washers and nuts on them to reassemble the heat box.
Sure it does not look like a factory build, but it now works.. So all good.

 

[misterjason]

I could not find any repro seal kits for the non AC heater box.
I ended up driling out the rivets that hold the metal backing on, then replaced the core and made my own seals.
I went to the local hardware store and bought some high density foam and made my own gaskets.
Here is a link to a few pictures. https://72mach1mustang.blogspot.com/2022/12/heater-box-and-decals.html
Unfortunately I did not take any pictures of the gaskets I made or the rebuilt box.

In order to replace the now drilled out rivets, I just used small screws with washers and nuts on them to reassemble the heat box.
Sure it does not look like a factory build, but it now works.. So all good.

Great! Thanks for the tips.