Overflow Box Too Small?

[tinpusher]

If I had to do it all over again I think I would buy a tank already set up. However my time machine is in the shop so here goes "I need help! Part XXI".

Bought and installed a pair of overflow boxes for my 125 gallon. Seemed simple enough just make sure they are big enough to get your hands around the stand pipe to remove when needed. 5" square should do.........wrong! With the teeth restricting flow over the lip I am not getting enough water to the sump. Aquarium fills to the point where the water is going over the top of the teeth which sort of defeats the purpose. Options?

1. Remove the teeth?
2. Remove the boxes and get them enlarged?
3.?????

Any opinions appreciated.