Source for 273 Head Gaskets??

Well I ordered a pair. Guess what? They have a 4.08 bore instead of the advertised 3.906 bore. So back they go. I did not measure the thickness since I'll be returning them.
So, What's The Answer?
The Fel-Pro 1008 Fel-Pro Performance Head Gaskets | Summit Racing say's it's a 4.180 bore.