[robo]

I have not gone for the sierra set up so I cant comment on it but dig about with the search and its was made clear that the offset mushrooms were used to give the suspension trail. That might or might not be correct so moving on to the basics and there is not enough caster in the system to give it self centering end of. i have gone for the mazda rx8 uprights and will be making fully adjustable top wishbones to address the problem. Caster is what is needed. If the mushrooms set the trail to zero that makes the whole thing worse!! Zero or close to zero caster and zero trail "no thanks"

Bob