Has a FIBA World Cup game ever ended 83-51?
Exactly once. On February 23, 2023, Australia beat Bahrain 83-51, and no FIBA World Cup game before or since has ended that way. When it happened it was a scorigami, the first 83-51 in league history.
That makes 83-51 the 475th most common final score out of 1,178 that have ever occurred in FIBA World Cup. One point away, 84-51 has happened never and 83-52 has happened 1 times.