As long as you have enough room to put the battery somewhere, it's doable. I had EMGs in my Bully SG from years ago (which had a relatively large cavity) and also EMGs in a Fernandes Ravelle (VERY small cavity, but I was able to tape the battery to the cavity cover and it was kinda suspended just slightly above the pots).
Besides changing the pots try using the emg 24 volt mod. This uses 2 x 12 volt camera batteries in a holder that connects to the 9 volt socket but is a smaller size and makes emgs sound much etter. EMG's are rated at 31 volts so using a 9v battery means their not even running at 1/3 power.