OP I think you are cruizin for a bruizin here on this. I think you should grit your teeth and heave that thing.
You know why people like Pitts and 4spd say stuff like they did?
Because when we were young, WAY back in the SEVENTIES, we bought cheap junk aftermarket CHROME ALLOY water necks and they LEAKED
I don't know whether the surface finish is wrong for the gasket, or the alloy is soft and warps or what.