Originally Posted by bad packet

correct, rear shocks don't control ride height. The size and position of the rear spring, paired with the spring rate do. If you take out the rear block it will drop the rear 1.25". If you add something back in to the mix that lifts the truck to back stock ride height, such as a helper spring, almost deflated air bag, or a road active suspension spring... you will want to go with the 4x4 shock.

Ex... I wanted to add RAS to my truck, but I didn't want the truck to be 1.5" higher in the rear when unloaded. So I removed the rear block, cranked the RAS to almost the 2mm setting, and swapped my stock 4x4 shock for a 5100 4x4 shock. Stock ride height, increased spring rate. Removing the rear block also reduces axle wrap... paired with the RAS virtually eliminates it.