One occured in 1951, when the NIT was probably the bigger tournament. The other occured in 1966, when the NCAA had most definitely overtaken the NIT in prestige.
And if you want to talk about NIT championships, Utah won it in 1947, when, as you said, the NIT was more prestigious. So the argument is null and void.
Another thing, after the Utes won the NCAA tournament in 1944, they played the winner of the NIT tournament in Madison Square Garden for an exhibition game and won.
My facts from my previous post still remain.