You don't need to do it if everything else is stock. Be careful where you grind on the AFC foot, and understand exactly what you are trying to accomplish before you start grinding.
If you've got the AFC adjusted to limit pre-boost fueling (heavy black smoke) with high flow injectors, you may find that the AFC foot isn't able to get out of the way at full throttle full boost conditions. If this is the case, you may want to grind the back of the foot so it can be moved further forward under full boost.