Has a College Football game ever ended 84-13?
Exactly once. On September 17, 1983, Nebraska beat Minnesota 84-13, and no College Football game before or since has ended that way. When it happened it was a scorigami, the first 84-13 in league history.
That makes 84-13 the 1819th most common final score out of 2,215 that have ever occurred in College Football. One point away, 85-13 has happened 1 times and 84-14 has happened never.