Thrust washer in back end of crank??

Just about to drop the engine back into the Riv and I noticed this ugly looking "thrust washer" in the back of the crank. It's a nice fit in the crank. Not press, but almost line-to-line. Ugly looking hole in the middle.

Is this thing stock?

 

What year and engine are you using?

 

1967 Riviera with the original 430.