[jeffschevelle]

Those are two good examples of what Fremont was doing in that time frame. You can see in the first pic that they were gang stamping the first 6 digits (7Z1396 in the first pic), then applying the last two digits separately. I speculate that they were doing the gang stamping in large batches so they would not have to change out the dies on every motor.

But if the engine did not actually get used before the car VINs rolled to the next 100 group, they would have to overstamp the last digit of the gang stamp with the next number. If you look closely at Bill's pic there is a 5 under that 6. They gang stamped 7Z1385, but had to change the 5 to a 6 because the engine did not get used one a 7Z1385xx car. I have dozens of similar Fremont examples from the same time frame.