yeh they are very picky. the rims i used to have were 26mm over standard and the legal limit was 25mm, got knocked back as well. they don't rub at all really.
i got stanza struts and adjustable strut tops in my ute and it's running a bit of neg camber. the only problem is track increase, my car is impossible to register in ACT because of the front track now.
just out of interest but if you are going to go to the trouble of adapting a motorcycle head to an a series why not just use the whole motorcycle engine? is it just to comply with certain racing classes?