Has an AFL game ever ended 61-8?
Exactly once. On May 10, 1902, Sydney beat Carlton 61-8, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 61-8 in league history.
That makes 61-8 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 62-8 has happened never and 61-9 has happened never.