Has an AFL game ever ended 47-8?
Exactly once. On August 5, 1899, Carlton beat St Kilda 47-8, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 47-8 in league history.
That makes 47-8 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 48-8 has happened never and 47-9 has happened 3 times.