Kevin,

Up under the adapter you have placed over the oil filter stand, there is a barely visible 1/8 npt opening for the stock oil pressure sensor. 

1/8 NPT may work, but I’m quite certain that is a metric thread – I don’t recall what size.

Al

 In your picture, it appears to be open.  It is hard to see with the adapter installed and can be forgotten till you start the engine.  You would be AMAZED at how much oil can come out of that small hole!  Plug it!  Don’t ask me how I know this!