We have a bulk head to close in permanently and it  is attached to a block wall, i was wondering what the best way to fill in the hole with since it will have earth place against it  when all is said and done.One thought was to fill it in with block but i wasn`t sure  if that would be strong enough to hold up once it is back filled.Another thought i had was since we have all the siding off the house right now would it be possible to cut a hole in the box(16-18“)take out the 2×6 plate the same width then put in some forms below and pump concrete in from the hole i just discribed . what would you guys do in a situation like this i`m just curious.