I'm not going to argue about grp'n' items....it's a whole subject itself.....we have the wrc setup on the rear of our car....but even this had to be tweeked to acheive 0 bumpsteer....if i was building a race car as you..i'd try and ditch the tube beam....go square and a pair of mag arms....the main reason for building the wrc car was to save all the weight in the back end and improve the car over the fast bumpy stuff...

Regards

Ian