Heater A/C ducts and butyl seals

[iTurbo]

I'm replacing the heater core on my Shelby CSX. I have removed the heater & A/C box assembly from the vehicle and have it cleaned up and a new heater core installed. I'm trying to get the duct work sealed back up, since a lot of the original foam was in really bad shape. Thankfully I've been able to replace some of it with some adhesive backed foam strips that came with new air conditioners for the apartment complex I work for. I was able to use some of this to recreate the foam gasket at the vent/recirc opening at the top of the heater & A/C box, and was able to glue some of the other original foam that had ripped with Super 77 adhesive.

Some of the other plastic ducting for the defrost etc.. uses a butyl seal according to the FSM. Is this stuff still available? If not, anybody have a good alternative? I'm wanting to get all the duct work sealed up as well as possible so that the blower motor blows out the correct vents with good flow when using the buttons on the heater & A/C control unit. I really want to get this installed as well as possible because the heater & A/C box is a royal pain to remove from the vehicle. I don't ever want to have to remove it again!

[135sohc]

Butyl tape is still pretty common. Another product I have been turned onto using is low expansion spray foam, more common to see the newer stuff using that because it gets into the cracks/crevices better.

[iTurbo]

Thanks! I will have to look for butyl tape and low expansion spray foam before reinstalling the thing. I've never used it before....hopefully NAPA or somewhere local has it or can get it.

[supercrackerbox]

Any parts shop that deals with a lot of paint/body stuff should be able to at least order it in.