What are those tiny freeze plugs for?

I got a freeze plug kit for my 273 the other day. There are 2 or 3 teeny little plugs that I see no place for on the block. Am I missing something or are they just for a different application?

Also found out my kit didn't have the plugs for the heads. Grrrrrrrrrr :banghead: more shipping costs in my future,,
Author: valiantone