If I have it straight in my head... (unlikely, but plausible) when there is a greater distance between CG and RC (moment) the larger effect on body roll is seen for the same weight... Like a cheater bar on a wrench, it has more leverage. Where the RC is in relationship to the rest of the car is how that leverage will impact what the car does. If the RC is below the chassis as apposed to above the axles, the effect will be different. This page is one I am digesting now: ROLL CENTER