I just went to look at a 1971 442 for sale
the seller says he bought it mid 90s has the engine rebuilt a while back and was told by the previous owner it was the original
I took a picture of the vin but how do I tell it's the original engine?

i did notice a eldebrock intake and a regular air cleaner even though it has the hood scoops

how can I find out if the engine is the one that came from the factory

 

drivers side front lower corner of the block has a "pad" area the stamp was done for VIN Nuber

compare that to dash # and vin on paper work

 

 

can I seen that by looking under the hood

or under the car

 

If the Olds has power steering
the lower , horizontal brace may cover the "pad"

under hood should suffice

 

This is what to look for

 

39Zxxxxxx tells us that this is a 1969 block from the Fremont plant. Fremont didn't build any Oldsmobiles with 455s in 1969, so what's the block casting number next to the oil fill tube?