[tubman]

It's not the gasket so much as the power valve itself. Later Holley carburetors used a power valve that looks almost exactly like those for our carburetors and screws into the carburetor just fine. However, the way they seat is different and they are prone to leaking if used. That being said, I would certainly expect kits from Joe's would have the correct ones. I think there is a photo somewhere on the internet that shows the difference between the early and late versions. If you can't find it, maybe I can.