I didn't think there was a Q code in 1969. I thought the Q codes were 71-73 with 351's 4v
I thought the 428 in 1969 were either R or O code
R was the 428 4v SCJ and the O code was 428 4v CJ
The Q code is the exact same thing as the R code but without the shaker, the SCJ option had no specific engine code number
Some just came with that motor, If you opted for the drag pack the car came with the special rear end, and the oil cooler, I believe that
this also triggerd the placing of the SCJ engine in the car.
LOL, I am learning Myself!