Dirt in the Engine

I originally made this posting over at the IFSJA Forum, but I thought maybe folks here would also be able to offer some great advice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

http://www.fullsizejeeps.com/gallery...0055/Dirt1.JPG

http://www.fullsizejeeps.com/gallery...0055/Dirt2.JPG

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.
http://www.fullsizejeeps.com/gallery...0055/Dirt3.JPG

You can oepn one of the two holes in the back of the block near the camshaft and blow some compressed air into the oil galley after you reopen the oil pressure sending unit. Heck you could even dump more oil in the back of one of those holes and try to flush the system out.

You mean one of those two holes, between the yellow bar?

http://www.fullsizejeeps.com/gallery...0055/Dirt4.JPG

EXCELLENT!
Thanx! Much relief for me!

Or get a reducer for your shop vac. I'm talking about one of those deals that lets you reduce the 2 1/2" hose down to 1 1/2", then you can get a tapered cone shaped nozzle, the end of which will fit in the hole and seal pretty good.

So, what is the mystery hole on the timing chain cover, near the oil filter?
Like I mentioned, my '78 model motor does not have it,
my '81 J20 does not have it,
my '86 Grand Wagoneer has the hole, but is pluged with a bolt.

What threads are in this hole?
If it is a special piece of hardware, where can I get the bolt/plug/special hardware to seal it?

That is where your pressure relief spring and plunger go.

Yeah, that's the oil pump pressure relief plunger/spring/cap hole.
All AMC V8's with stock oil pump cover / oil filter adapters should have that "port".
If you have AMC V8's without that hole, that's wild.
Not sure if they'd have the "screw" or "plug" at a Jeep dealer or not.
Should also be an aluminum or copper sealing ring washer also.
New Plunger & Spring comes in oil pump gear kits available
from your favorite local auto parts store by Sealed Power.