Engine Builders-KB356 Piston Milling

23 cc's is with the piston in the hole , tdc.
The piston, like that..will be entirely sub deck...below the deck. The quench pad unmachined comes up .080 above the deck normally.

You should measure with one piston n rod assembled on the crank in the block.
I spec with a 60cc...and no quench pad..that you would be near the lower 9.1 realm.