Fair enough and I understand that he's doesn't want to buy pistons, why I said if this a one time build go ahead and mill the **** out of it. But if this short block may live on in different incarnations "I" would go with proper pistons. If he don't want to under any circumstances that's fine.
I'm sure a zero decked stock piston engine gonna have less clearance than aftermarket pistons with decent valve relief's. Is that ever gonna be a problem for the OP probably not but could be a limiting factor in a future upgrade if that's possibility.