I think I got mine from limolarry on ebay. If you search heat riser tube Buick you will find it. I bought one from Ames first, but it wouldn't work. The one off ebay has foil inside, but the right appearance outside. It's nicely shapeable, too.
Air cleaner pre heater hose, that is what I thought. I like the black ones over the silver ones. Looks better to me. http://www.amazon.com/dp/B000C7ZBXW...e=asn&creative=395105&creativeASIN=B000C7ZBXW