That is just the casting number, it only tells you the actual origin of the casting, more numbers that would be pertinent are the casting date, which is cast into the block on the passenger side. From that you will be able to discern the year of the engine, which allows you to look for the location of the partial VIN. 68 had the partial VIN on top of the drivers side bellhousing flange, 69 and later would be on a pad on the passenger side, right above the oil pan. There are also assembly numbers, engine displacement numbers and a few other identifying stamps on the driver side front, right below the head.
