Has a FIBA World Cup game ever ended 83-61?
Exactly once. On February 26, 2018, Argentina beat Paraguay 83-61, and no FIBA World Cup game before or since has ended that way. When it happened it was a scorigami, the first 83-61 in league history.
That makes 83-61 the 475th most common final score out of 1,178 that have ever occurred in FIBA World Cup. One point away, 84-61 has happened 3 times and 83-62 has happened never.