Has a FIBA World Cup game ever ended 78-56?
It has. 78-56 has been a FIBA World Cup final 3 times in 2,041 games. The first was Germany beat Egypt on August 7, 1994; the latest was Greece beat Estonia on July 2, 2018.
That makes 78-56 the 96th most common final score out of 1,178 that have ever occurred in FIBA World Cup. One point away, 79-56 has happened never and 78-57 has happened 2 times.