[nUcLeArEnVoY]

Prepping for a heater core replacement and am scoping out under my dash to see to what degree of molestation (or a lack) that my car has suffered. Everything looks to be there.

One thing I did notice is that the foam seal that goes between the main AC duct under the glove box to the heater box has degraded to nothing. There's still some remnants. It seals to a plastic square shaped adapter on the heater box held in by two screws.

What I don't get it, just how freakin' thick is the foam seal supposed to be? Because there is a good 1" or more gap between the opening on the main AC duct and the adapter on the heater box, and I know it once sealed since you can see the witness mark on the adapter. No wonder I felt barely any air coming out my vents, it's all escaping through that gap and not making it to the main duct to distribute through the rest of the system.

I saw on another post that this missing seal is the main reason behind poor vent output and in my case it definitely makes sense, but why such a huge gap? My duct looks like it's installed correctly (tho the mounting points are broken, but I have a new repro duct on the way), so I don't think it's that. What do people use to replace this seal, because I don't see it for sale anywhere?

Thanks.