[jeffschevelle]

If you are talking about the engine "RPO" box (line 2 box 11 on a 69 body broadcast sheet), that corresponds to the code that the salesman was supposed to enter on the new car order form to order that optional engine. In 66-67 some of them were single-digit numbers and some were single letters, but all were a single character, and had nothing at all to do with the engine suffix code. Don't know if that remained true in 69.

If you can find a 1969 dealer ordering instructions book it would have that code in it. I have those books for 64-67 but I don't think I have a 69. I will double check this weekend though.