i'm thinking the .0095 might be the spec for removing 1cc of chamber volume ?
as far as i know, the .0123 on the intake face for every .010 off the deck surface is the same on both the big and small block engines.
that is so any intake can be used, and not locked into a specific head combination.
the amount needed to remove 1cc from a head chamber is more than likely speced for a particular head casting.
i'm sure more knowledgeable people will chime in with correct info.