I searched and the only place I could find one is Summit and they wanted $21.34 for one. It was only 12 something for the gasket with supposedly free shipping, but they charge you $9 for the handling. That's almost as much as the gasket itself. I don't know what kind of handling would cost $9.
It just a scam so that they can say free shipping.

 

just buy a new stock one and stick it up to your 58mm tb. Then get a hammer and LIGHTLY tap the edges of the bores. It will cut the gasket perfectly to match the bores. Thats what i did.

 

Thanks, I never thought about that. I have to get a complete gasket set for my motor since I'm completely rebuilding it anyways. hopefully one will come with the kit.