Has a FIBA World Cup game ever ended 104-55?
Exactly once. On August 24, 2006, Spain beat Japan 104-55, and no FIBA World Cup game before or since has ended that way. When it happened it was a scorigami, the first 104-55 in league history.
That makes 104-55 the 240th most common final score out of 863 that have ever occurred in FIBA World Cup. One point away, 105-55 has happened never and 104-56 has happened never.