Also for the valve cover I bought, this is the seller.
Part Number: 12642655. FOR SEATBELTS -MUST BE VERIFIED BY VIN LEFT=DRIVER SIDE, RIGHT=PASSENGER SIDE OF VEHICLE. THESE ARE GENERIC ILLUSTRATIONS OF WHERE PART MAY BE ON VEHICLE, NOT ACUTUAL PART.
www.ebay.com
Came in a nice brown box with the GM tagging and a nice "official" seal on the end, like i would expect.
Finish on the valve cover was a little different than the one from the cheaper seller.
Also there are the expected numbers protruding from the inside of the valve cover, like the OEM.
Made in Mexico casted in there too.
The cheaper cover looks good via the pictures, but if it's an accurate picture then it's a different casting than the one I bought.
For reference,
The cheaper "OEM" that i didn't take a chance on:
https://www.ebay.com/itm/193794292910