Hi !!! ...... CPP references that the QA1 coilover spring/shocks offered will not "work" with the less expensive tubular control arms offered on several pages and lookups. May i ask why ? I'm assuming it might be a liability or strength issue with the "spring bucket" being 2" lower but other companies have no issues or notations .... What's cpp's reasoning ? I would buy and apply the c5 brake kit to these if it weren't an issue. I won these arms in a raffle and they look quite sturdy and with upgraded ball joints have been used by others with great success .... Please advise .... Best regards, cw