That VIN belongs to a 1969 340 Swinger that was built around the first week of December 1968. What is the casting date on the block?? That is not a 1972 VIN.
Yes, the year was figured out and posted when he put up the correct vin. You will even find the exact day it was assembled in another post and it wasn't in December.
Did you read the thread? The casting date was also posted earlier.