What is this?!

[rod1701]

Started as an innocent clean up and detail project but ended up taking off the front and top of the engine to clean, paint, and detail. Took a few pics so I could put it all back together. It for the life of me don’t know where this came from and dont see it in n only of the picks. In all likelihood it was black and covered in 40 years worth of grease like everything else.

Pretty sure it’s from the power steering pump side but for the life of me, can’t figure it out.

Looks as if someone may have hacked at it with a grinder on the inner curved part.

Also, was originally an A/C truck but compressor is long gone. Everything seem to line up without it. But haven't started or drove it to see how if its stable/strong and w/o wobble.