Maybe that explains the huge sound
I am not aware of any non G&L factory route's that the MFD's will fit into. Some EMG's are pretty big but not as wide (vs long). The other thing that might put a hitch in things is the rounded corners on the G&L pickups. Remember too that these suckers are pretty deep. Depending on what they are replacing you may have to route deeper too.
What are they going into?
At least they would be easier to route than a music man pickup.