Has a FIBA World Cup game ever ended 77-64?
Exactly once. On August 8, 1998, Spain beat Argentina 77-64, and no FIBA World Cup game before or since has ended that way. When it happened it was a scorigami, the first 77-64 in league history.
That makes 77-64 the 240th most common final score out of 863 that have ever occurred in FIBA World Cup. One point away, 78-64 has happened 1 times and 77-65 has happened 1 times.