new mystery

ok i need help again.can anyone tell me were the vin number is on a early 68 318.the casting date is 8/1/67.this is were the mystery comes in ;i was told the motor was original but the build sheet says the car was built 8/1/67.is this possible i always thought the motor was built a month or so before the car.i know were the vin is on my 68 and 69 340s but there is no pad on the 318 .thanks