Has a Serie A game ever ended 7-4?
Exactly once. On December 24, 1950, AC Milan beat Atalanta 7-4, and no Serie A game before or since has ended that way. When it happened it was a scorigami, the first 7-4 in league history.
That makes 7-4 the 37th most common final score out of 40 that have ever occurred in Serie A. One point away, 8-4 has happened never and 7-5 has happened never.