Nice picture...

The above is correct. Do not think its going to allow dirt and crap to get into the engine. This is a very poor design drain that goes down thru a casting and exits at the bellhousing flange. Then it spills out down over the starter. It cannot ever pour down the drivers side of the engine. There is a casting web that makes it only spill on the starter... Really bad idea. This nut is no longer made either so don't loose it. To remove or tighten it you need a 3/8 drive socket wrench and extension. When Ford discontinued them I bought 11% of the last stock so I have a "few" for a just in case issue. Sorry to tell you this but its going to be tuff finding that turbo drain grommet. Try a member here named Russ... He goes by typ4 and may have a few grommets...