I like 915's and agree that with quench, that pump fuel will work up to 10:1 easily....The problem is, getting 10:1.
If the 915's have been cut at all, you'll get more than that.
With stock size manley valves, my 915's cc'd at 78.
With .043 quench, and the valve reliefs in the speed pro's I'm a little over 10.6:1
I find it's a little much on pump gas, when I'm at sea level, but doable where I live (3600 ft)
Camshaft becomes a variable here too, so there is a lot to consider. Run a 915 headed, quench 440, with a stockish cam, and I have no doubt it will ping like crazy.
FWIW, I dismantled a 67HP 440 block, and the pistons were .067 in the hole.(plus .020 gasket and thats .087 quench area
)
Quench wasn't a consideration for them back when they made them.