Has a FIBA World Cup game ever ended 83-53?
Exactly once. On February 25, 2018, Iran beat Iraq 83-53, and no FIBA World Cup game before or since has ended that way. When it happened it was a scorigami, the first 83-53 in league history.
That makes 83-53 the 475th most common final score out of 1,178 that have ever occurred in FIBA World Cup. One point away, 84-53 has happened never and 83-54 has happened never.