I'd recommend toe-in instead of toe-out in this case, as it won't be as twitchy off center and should track straighter. Steering linkage needs to be checked at all pivot points for binding and/or sloppy ball cups. Last thing to check would be the servo saver, as they do wear out with use. Larger, heavier tires wear out the servo saver spring a lot faster than smaller tires do due to the forces applies whenever the tire hits bumps while turning, and warrants a more frequent replacement of that part.