The last time I went to Autozone, they did not have it in stock. He said they usually stock it but ran out. I ended up getting it from Bill Jenkins
www.teamfordparts.com.
Make sure you get the correct TB gasket as SVT is different from non-SVT.
Regular non-SVT Duratec
F5RZ-9E936-A
SVT Duratec
F5DZ-9E936-AE