I have them on SNACC as:
Dispatch NGCB Disp 34800
FS 1 NGCB FS 1 34768
Tac 1 NGCB Tac 1 34736
Tac 2 NGCB Tac 2 34704
Tac 3 NGCB Tac 3 34672
I got these from an old list and do remember hearing GCB traffic on one or more of them a year or so back. They weren't very chatty if I remember right, and it's been a while since I actually listened to my BCD396XT.