Large valved 273

yr wrote

"The biggest things about notching the bore are keeping the notch inside the gasket sealing ring"

you want to keep the notches away from the edge of the combustion chamber
you want to keep both the notches and combustion chamber smaller than the gasket
put the heads on the block, dykem and scribe deck around the bores AND scribe the gasket
and then scribe the top of the block using a hook with the heads onor using the size of the chamber taken from a templet you make
with core shift you want to check each chamber
it does not take much chamfer to make a difference- a square sharp edge shears and is a no no