Check EVERYTHING... even things as simple as sway-bar mounts. It's unusual that only the passenger side would drop 1" lower, if the install method was identical on both sides. Also, make sure the shocks are torqued to roughly 30ft/lbs...

Spring pads, once in place, don't move. And the springs settle a TAD but nothing crazy like an additional inch. Mine only settled 1/4", if that.

Which Bilsteins did you order, out of curiosity?