i would say that mopar has not done a good job marketing their springs. the 002/3 springs are designed as the only SS springs that are for racing. in my opinion the 456/7, etc springs are glorified street springs that are adequate for occasional trips to the track. the 002/3 are specific to the 1968 A body SS cars, but do very well on B bodies. as herb mentioned and i have detailed in previous posts, your suspension has to work together as a system. if your front suspension and pinion angle are not set up correctly then it doesn't matter what springs you are using.
you have seen video of my car launching, those are 002/3 springs and are quite adequate.