Has an AFL game ever ended 66-39?
Exactly once. On July 24, 1965, Carlton beat Geelong 66-39, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 66-39 in league history.
That makes 66-39 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 67-39 has happened 6 times and 66-40 has happened never.