I have some of the O-ring boss plugs like used on fuel pumps and things. The thread and O-ring is correct. The problem I had with them is the hex head would not clear the block around the hole.

I will look and see if I can find some with the allen head in them. Thanks for the info.

Hopefully someone will come up with the galley plugs for the oiling circuits. I am missing three and would buy more just to have them. These are the ones held in by snap rings and have the 1/4" 20 thread hole to pull them out. The have a recess and oil ring for sealing the hole.

Leon