The largest margin of victory was 30 pts in a champtionship game. Not sure about just tournament games.
The largest margin of victory in the men's final was in 1990 when UNLV beat Duke by 30, 103-73.
The largest margin of victory in an NFL game was 73 to 0. This happened when the Chicago Bears defeated the Washington Redskins during the 1940 NFL Championship game.
I'm pretty sure UNLV beat Duke by 30pts in the 1990 title game
The 1990 champion was the UNLV runnin' rebels over Duke by a score of 103-73 which is also the largest margin of victory ever.
In 1963, Loyola set the NCAA tournament record for largest margin of victory (69 points) with a 111-42 victory over Tennessee Tech in the first round.
Super Bowl XXIV
The largest margin was 77 points against Georgia on February 27, 1956. The final score was 143 - 66.
UCLA has the record for winning by 49 points
1965 regional - Princeton 110 - Providence 70