I would just take a drill bit the size of the hole in the block and run it up from the main bearing to make the hole line up with the bearing if it bothers you. Me, I'd run it how it is.
Also, if you do drill it out make sure you peck at it.,if the bit catches it will tear the bearing up. Just use caution if you do drill it.
BTW, you will need a long drill bit. MSC has them as well as other places.
