Okay, I can verify that the material used in the artificial corks they use for sealing up some liquor bottles (e.g. Costco Kirkland Gin and Tequila) will hold up to the manifold temperatures on an SS which I would think would be just as hot or hotter than on the NA engines. I took the car on two long 600 Km (400 mile) runs through the mountains driving it fairly hard and the makeshift airbox mounting grommets I fashioned out of artificial cork material held up well to the environment - at least in the short term. Can't say if the material would degrade or get all stiff and crumbly after a year or two because I only had it in there about a month. The design I came up with using the beer tab as a retainer didn't work too well but at least we know that the material will work so that if anyone wants to try and come up with a home made replacement for the HHR airbox grommets that might outlast the stock ones, there is a material worth experimenting with. I'm thinking a two-piece grommet design with some sort of retaining clip like a circlip might work.

 

How about some pictures ?

 

Got any pics?