I bought a pair of GM ones from the dealer a couple of months ago. A friend of mine works there and he hunted them down but I forget if regular dealers had them or if he got them through GM Vintage Parts. Some of this stuff is still out there you just need a cooperative parts guy to hunt for you.
For what it's worth, I compared the Victor Reinz valve cover gaskets versus the Felpro. Victor Reinz were a better quality. Carquest sells them.:biggrin: