the 'definitive' answer would be if the EIN ( last 8 digits are the same ) stamped on the engine matches the VIN on the car.
your car already doesn't match between the trim tag and the VIN. the trim tag shows the car to be a v8 ( -434 and should be -433 to match the VIN ). which does not mean that someone faked your car. back in the 60s and 70s, typographical and paperwork errors weren't all that uncommon from the factory.