There has been written a lot about the 777 engine diameter being bigger than the 737 cabin diameter. Some say it is true, and some say it is not true.
But according to GE and Boeing's homepage I have snatch the following facts:
GE90-115 B, the powerplant for B777-300ER has a diameter on 135 inches witch equal 3,43 m.
The interior cabin width on a B737 is 3,40 m.
SO THIS MONSTER ENGINE HAS A BIGGER DIAMETER THAN THE B737.