Yes in the early years they were advertised 9.0; but as I recall with small bore 020 metal-shim head gaskets, and since the total chamber volume to get to 9.0 is 70.2cc, you can see where this is headed, after a rebuild.
First, you're not gonna find those gaskets, and Second the bore size is increasing, and third, after 55 years, you can bet the valves are no longer in their original locations. So
By the time you bore, clean up, and assemble that engine; you can bet it ain't gonna be at 9/1 anymore without other machining. Simple math puts it at 8.8@zero-deck, before decking or milling, with the already existing 040 overbore; and in post #1, OP states that he wants to do as little machining as possible.
So yes, I used the wrong Scr numbers (7.76), but I used those wrong numbers correctly; and the results while not exactly correct, still speak to the same problems and results.
And yes, I assumed the OP was at least thinking of up-camming cuz why else would the title say what it does.
I'm gonna stand with my post for now; but admitting and apologizing for the rather large Scr error.