I think I managed to save my block by removing a broken easy out from the coolant passage drain plug. I had to drill a small relief hole to accomplish this which cut into the threads a bit. Looking for options to best address this... I figure I have three or four solid approaches but please feel free to comment or suggest others.

1-simply drill and cut to the next size up (3/8-18npt) drain plug (currently at 1/4-18 npt)
2-use the thread repair compound in the picture (prior use-good stuff)
3-drill & press some sort of bung so I can stick with the same size plug
4-shut up & let the machine shop address it no questions asked

I am leaning towards 1 or 4 or a combination there of... What do you all think?

Three pictures from different angles to best show what's going on:







And the thread repair compound:

 

I would probably go with #1.

 

1 or 4
you might try 5/16 before going 3/8

 

I would love to go 5/16 npt but I can't find that to be a standard size.

 

my bad Missed the NPT

 

Looking at the soft plugs and the crap on the other side of the drain plug....looks like a good cleaning is next.
I'd just use a 1/4 pipe tap first and see how a new plug fits.

 

It's going in for a hot tank treatment today. Definitely needs cleaned out.