Has an AFL game ever ended 83-78?
It has. 83-78 has been a AFL final 7 times in 16,622 games. The first was Richmond beat Melbourne on July 14, 1923; the latest was Geelong beat Footscray on June 18, 2021.
That makes 83-78 the 191st most common final score out of 6,607 that have ever occurred in AFL. One point away, 84-78 has happened 5 times and 83-79 has happened 4 times. At one point the score disappeared for 57 years, between 1923 and 1980.