Has an AFL game ever ended 120-24?
Exactly once. On May 12, 1928, Carlton beat St Kilda 120-24, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 120-24 in league history.
That makes 120-24 the 3884th most common final score out of 6,649 that have ever occurred in AFL. One point away, 121-24 has happened never and 120-25 has happened never.