From what I've noticed, the ceelings inside the Boeing narrow bodies, are much much lower than those in the Airbus narrow bodies. I've flown on the A319, A320, 727, 732, 733, 735, 738, and the 752. Even with the new interior in the 738, the ceeling felt and is much much lower than the airbus counterparts.
The 777 has a pretty high ceeling. I belive that it is around 11 feet high.