The eight-team Dixie Classic was much bigger than the Big Four. The Big Four and four visiting teams. Part of it was the timing. It took place between Christmas and New Year's. It was part of the holiday fabric of the state and it helped that school was out and many people weren't at work.
And in a time before TV covered much college basketball it gave local fans a chance to see such exotic teams as Cincinnati, Utah, Michigan State or Oregon State.
The early '60s point-shaving scandal killed it. State-supported schools UNC and NC State had their non-conference schedules cut back for a time.
But not Duke and not Wake Forest, both private schools not implicated in the scandal. So in the gap between the end of the Dixie Classic and the beginning of the Big Four Duke and Wake Forest played a non-conference game in Greensboro every December. This was in addition to the two ACC games, of course.
So, there is a precedent for this sort of thing. And with the Southern Conference/ACC Tournament thrown in it was possible for Duke to play its Big Four rivals four times in a season. And it did happen.
But my initial response to the possibility of an additional Duke-UNC game is why mess with college basketball's premier rivalry. Leave well enough alone,