Has an AFL game ever ended 91-66?
Exactly once. On June 20, 1936, Essendon beat Hawthorn 91-66, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 91-66 in league history.
That makes 91-66 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 92-66 has happened 4 times and 91-67 has happened 5 times.