The thing about cal-tracs is that they were originally created for GM and Ford leaf springs that are much more symetrical in their layout than a Mopar spring. Look closely at the front of a cal-trac hanger and you can see that when they start their pivot action, they essentially turn a standard spring pack in to an SS pack by shortening the effective length of the front segment several inches. You can tune a cal-trac to create this adjustment faster or slower than you can with an SS spring pack, but the net result is the same. It also is easier to tune a cal-trac by simply adjusting the bar length, whereas tuning an SS spring requires adding/removing pack clamps on both the front and rear segments and is a much more time consuming method.
Another thing is if you have an SS spring pack tuned correctly, you never need a pinion snubber either. The whole means by which an SS pack works is by creating body separation. If the pack is doing its job, the body lifts away from the axle and the snubber is simply left hanging in the air.