I found numbers on the case right behind where my fuel filter is positioned. Double humps on the heads not sure if that makes a difference but I just can't read the numbers in the amount of light in my garage. It almost seems like the orange paint on the motor was laid down so thick that it covered the numbers. If it weren't raining here I'd take it out and look in better light but you know how it is...don't want to get the car wet!