iam using the fatmans,i dont think my susp. will work without them. fatmans are 2 inch spindales. here is a note from the new ones from magnum......first time i read they are 3 1/2 inches dropped
How low will my Mopar sit?

The typical dimension of greatest importance is that of the forward-most edge of the frame (core support area) to the ground. This dimension ranges from 10"-12" but is altered by tire diameter and the installed height of the coil over assy. It is not recommended to adjust the coilovers lower for suspension geometry and misalignment reasons, unless our dropped spindles are used, which can allow the car to go another two inches lower for a total of 3-1/2" lower. Custom headers may be required if using our 3-1/2" dropped spindles unless big diameter wheels are used (ie 20"). Here is a more accurate dimension accrued from a 73 Cuda. With a 24" tire and the coilovers at 12" installed height, the distance from the ground to the frame is 11-1/2". This suspension has 4-1/2" of travel measured at the spindle tip