I assume you meant 'front gallery' plugs? Now that is interesting... made me go look at my unmolested '68 273 block.... no plugs in the front. So just the plate in stock form.
One thing I did not realize is how close behind the front of the block that the oil passages to/from the #1 main bearing sit in the galleries; it is less than 1/2". So you had better not drive any such front gallery plugs in too deep. I wonder how often THAT has happened.....