REAL COPO? saw what I think is REAL see my pics

[Les Quam]

Its rough cast near the oil filter on all Chevy big blocks or just the 512 and 396/375 blocks? I didn't know there were 512 blocks without stampings so they could later be restamped? You would have thought Chevy would have stamped something to denote it was a warranty or parts block? So then to create a bogus COPO you find a unstamped block and restamp the rough area and machine the pad on the front and then restamp that and get some bogus paper work and your in business? Geez that sucks. So absent prior owners and bulletproof docs how do you make sure its a real COPO or not? 3/8 inch fuel lines and specfic motor mount part numbers seems flimsy?

I would think the Yenkos would be easier since the VINs are known and you can check the two VINs on the body for welding???