I my '68 Barracuda matching numbers?

Casting numbers are, well, cast into the block. And many times blocks are cast well before the car and engine are assembled, and don't forget 68s actually came out in late 67, same as today's new cars.
My block was cast in January, and the assembly stamp is May.
I believe VINs are stamped in, and 1968FormulaS340 posted a great pic, and the assembly info is also stamped on the front of the block, (it is for BBs, pretty sure for SBs).
How someone who worked for Dodge would not know any of this is strange to me.