I'm pretty sure that's what we are going to do. I asked my shop to have one shipped to him overnight. I have heard pretty good things about hydroboost. Yeah the 7 inch is a duel diaphragm unit, but it feels as if it did when I had 4 wheel drums on it. Very odd. Just when you really stepped on it, is when you could feel the difference. Is there a different unit, or units to get, or is it one serves all? Thanks for the help by the way