Has a FIBA World Cup game ever ended 98-91?
Exactly once. On July 9, 1986, Australia beat Israel 98-91, and no FIBA World Cup game before or since has ended that way. When it happened it was a scorigami, the first 98-91 in league history.
That makes 98-91 the 475th most common final score out of 1,178 that have ever occurred in FIBA World Cup. One point away, 99-91 has happened 1 times and 98-92 has happened never.