I believe that's simply a piece of 3/8" steel tubing that's press-fitted into the block. You could probably run a tap into the inside, and use a bolt, a nut, and a stack of flat washers to pull it out. Then just tap a new piece into place with a little red Loctite to help hold it in.
Jerry
Last edited by Hotrod Lincoln; 10/12/2013 8:25 PM.