small plastic semi-circle piece under oil pan gasket

[Squishymonster2]

I am replacing seals and gaskets on a used '93 4.0 to go into my '94 Explorer. I took the oil pan and gasket off of the '93 engine. On the rear of the engine, inside of the semi-circle portion of the gasket channel, there is a thin plastic strip that is about 1/8 inch thick. This part came with my oil pan gasket so I decided to replace it. It is difficult to remove from the channel. I broke it in half then attempted to pull the two halfs upward, but there are plastic tabs on each end that are resested into the engine block and are stuck for some reason ( I think it's RTV sealant underneath ). So now I JUST the tabs are left in the engine block and the plastic strip is broken off. I need to know how to get these out. The best thing I can come up with is to use a very small drill bit and drill a hole into the plastic. Then either put a screw in it and pull, or just keep drilling and digging with a small knife until the plastic is obliterated. Is there a chemical I can put in there to completely losen the pieces? Then perhaps try to pick them out with a knife or needle.

What is this part for anyway?

On another note, I accidentally ordered an oil pan gasket a '94 engine when I actually needed a '93. I was under the impression that the engines were exactly the same but this is not the case. The '93 oil pan has a small groove in it all the way around the sealing surface, and a thin rubber gasket fits into this groove. The '94 has a flat sealing surface and a flat metal rubber gasket with rubber around the inner ring.

I decided to use the '94 oil pan and gasket on the '93 engine. The pan seems to match up the same as the last one but I'm curious to know if I'll have any problems.

 

[Squishymonster2]

After looking closer, I realized that the holes I needed to get the plastic out of were not part of the block, but the rear main cap, so I pulled it out, cleaned, and reinstalled.