F250 Steering

I have a 2002 F250 that tends to wander in the steering, only really noticeable when not towing, I seem to remember being told by at least two F250 owners I met in caravan parks that the RHD Australian versions come with suspensions still set up for driving on the LH side of the road. Driving on the LH side means the road falls left to right opposed to right to left when driving in Aust. so in theory there is cause to beleive a change in suspension set up may be necessary. I was told a fix was available but unfortunately I didn't ask specific details or where it could be done assuming a Ford dealer would know all about it. How wrong, Ford don't seem to want to know anything about it. Can anyone shed any light on the subject and what is needed to fix the problem. I recently replaced tie rod ends that showed minor signs of wear after 100,000Km but this did nothing to fix the problem.Wheel alignment etc has all been checked in accordance with Ford specs.(although probably against data published for the US) and everything else in the front end checked for wear. No sign of any abnormal tyre wear either.