Has a FIBA World Cup game ever ended 55-49?
Exactly once. On October 26, 1954, Israel beat Chile 55-49, and no FIBA World Cup game before or since has ended that way. When it happened it was a scorigami, the first 55-49 in league history.
That makes 55-49 the 475th most common final score out of 1,178 that have ever occurred in FIBA World Cup. One point away, 56-49 has happened never and 55-50 has happened never.