Different plants applied the frame dates uniquely - ie; vertical vs. horizontal and right-side-up vs. upside down. So, if you can see yours - clean it carefully until you can make out the sequence.
For example, the '70 Novas were right side up, driver's side, yellow, rolled through a stencil, with 'MAR 70' syntax. Yet, this '69 Camaro or Nova (??) is completely different, upside down, white, no letters:
