As stated the SS springs have the shorter front segment that controls pinion wrap/roll. This creates less leverage. The longer front segment stock style creates more pinion leverage there fore a snubber can be a way to control this effect. Now considering the pinion adjustment. You are trying to align the pinion to the drive shaft under load. The snubber can help with this as it will control over wrap or positive pinion wrap over 0%. The car on the ground should have about 3% to 5% negative angle (pointing down). This will be dictated by HP and Torque the car generates. This can be achieved with tapered shims. Another consideration is the tire contact patch when you launch the car. The more pinion travel you have the more initial tire contact patch you create. This helps eliminate tire spin. Suspension tuning can be an art and is very unique to each car. This can be fun when you are looking for every hundredth of a second you can find.
Good luck