1970-1971 340 vin pad locations

I understand for 1970-1971 340 blocks, there are 2 vin pad locations?

-one above the oil pan on the passenger side and one under the driver side head in front of the block correct?

I asking because I was looking at a car and both pads have vin#'s stamped on them, but only one pad matches the vin tag.

Also, the casting for the block is 7 weeks later than the car's build date. Wouldn't that be alittle late (I mean as a "general" rule.....I know there are exceptions it seems to everything)

Thank you for any help!

the one under the head is not a VIN stamp. It's ID's the engine and how it was built.

Thanks
Then almost 2 months separation is in the correct range for block date to build date?

340 has numbers stamped just below the head. Where it was built (which engine plant) If it uses premium gas or not, the date of assemble, how many bulit that day
Bob

The front stamp is the engine 'serial number'. It was stamped when the engine was completed.

After completion, it was readied to ship to an auto plant with other assembled engines.

When a car was coming down the line, an assembled engine of the correct type / application was sent to the main line to be installed in a car.

Just before the engine and transmission were mated to a car, the VIN stamps were done.

Car 'build dates' were not recorded back then.

This should help