There is a barrel screw where the throttle and return cables attach to the carburetors. I suppose you could get some slack there. I do not know if there is a quarter inch, however. Also, the barrel screws at the grip itself has some slack. I suppose in the worst case, you could unhook the cables from the carburetors, attach the cables to your new grip, then reconnect to the carbs. Keep in mind you want the system to have sufficient slack to operate smoothly and without binding.
The tank is easy to remove. Besides, on the Aero 1100, the tank does not need to be removed in order to access the throttle cables on the carburetors (it is easier with the tank off, but it can be done). Take a look. There are two screws that hold the cable bracket to the carbs. Remove them and you can easily unhook the cables from the carbs. Then attach the cables to the throttle grip and then re attach the cables to the carbs. Lastly, attach the bracket to the carbs and voila, you are done.
