I assumeyou are saying stocker as in race roller stocker ... and that would be my unlimited advice as well ... to be completely honest unless any of us are running wide open balls to the wall speeds we do not need anything better than the rtr chassis ... my first 8t was great being rtr ... unless your sdponser insists on getting you a tuned flex chassis I wouldnt buy one myself ... which is my point , that to get fast we need to run a stiff chassis and stiff buggy/trug altogether ... if you are turning laps at the tops of the polls at your track maybe look into tuned flex ... rtr is just fine unless chassis is a great deal