Heater Assembly Gaskets/Seals

[cshanek]

Greetings ...

I am in the process of replacing my 1964 C20 Heater Blower Motor, and Heater Core (Deluxe). I ordered the standard seal/gasket kit from class parts (https://classicparts.com/1963-66-heater-gasket-set?), which appears to match what is sold on LMC, and I could really only figure out the location for 2 of the gaskets. I dug around the web and couldn't find any help. I did buy a tube of high-heat gasket maker, so that is an option. I also spent a good deal of time scraping/sanding off the remnants of the previous (liquid) gasket. Questions ...

1. What parts of the heater assembly actually require a gasket/seal? I currently have the thin, rectangular-ish gasket toward the top of the assembly, and the gasket in the cab that goes around the heat duct.
2. If I need to seal between the lid, heater motor, or air box, how do you feel about using the liquid gasket stuff?
3. Are those other gaskets I have (see photos) for another assembly/variant or I am missing something obvious?

Thanks in advance for info/pointers.

-Shane

[AcampoDave]

No gasket on my airbox lid at all. I never knew there was one. My heater works just fine without it anynow.

[VictoriaHardware]

GM sealed the lid with black strip caulk. Applied to the top edge of the box perimeter, then the lid was placed and screwed down. Some can be seen stuck to the lid bottom here, the whitish lines.

The Deluxe Air (RPO C42) box also had sheet foam that went on both sides of the "flapper door" - the valve that moves when the lever on the side is rotated.

[cshanek]

I appreciate the pointers. That gels with what I saw when I was scraping things off, though I think I saw the black strip caulk on the top 2 levels (lid and piece below lid). I just replaced all the interior components and I'm waiting for the heater core to arrive.

-Shane