I originally made this posting over at the IFSJA Forum, but I thought maybe folks here would also be able to offer some great advice

As I was cleaning my spare motor, thinking about great it will look in gloss black, when I noticed the oil pressure sending unit and adapter was missing.
I dunno how much water got in.
What's worse, I saw a spec of dirt on the thread of the hole.
I thought, "I've got it get it out", so I stuck my finger in the hole to wipe the dirt out.
BUT, I knocked the spec of dirt in.
I am such a klutz!

I immediately ran out to Lowes and bought a plug and sealed this hole.

So, what to do?
Have I ruined this motor by introducing water and dirt in where it should never be?
Can I take the oil pan off or something to clean this?

Should I just relax, take a deep breath.
Then, when I am ready to start then engine, (Long ways away) do an engine flush and let the oil filter catch the dirt?

Here are some pics:





What is this hole near the oil filter, where I have this plug installed?
The '78 model timing cover that I have does not have this, but this '89 does.
The threads are not 3/8 NPT, but something else.
The 3/8 NPT pipe plug is finger tight, just seal the hole, but not to damage the threads.