Hey that buggy looks familiar.

Hope you enjoy it.
For your GT, how about rotating the servo 180 degrees so the bottom of the servo is on the right side of the truck instead of the left. It looks like you'll end up with more room for a battery on the left side of the truck. You'll have to drill new holes and maybe space the servo up a little to clear the lip of the chassis to do it, but it doesn't hurt to try and mock it up that way to check and see if it does increase the space availible. Kinda hard to tell from the pics you know.
You could always shorten the turnbuckle going from the servo horn to the bellcrank, moving the servo forward and giving you some more room too.