Just as an FYI for those looking for rear replacement shocks- PRG Greg is working on direct replacement COIL OVERS for us curtesy of communications with Pops, ntrdraggn, and I like to think myself also a tinny bit. lol.
blackArmada has the right of it though... currently Bilstein does NOT make rear shocks for the Armada- no matter what year it is or if it has auto-level or not. I believe is is also correct in that Polz did do a write up on his conversion of some 5100s to make them fit in the rear (not sure if he was able to get the valving correct or not).
'05 Mada LE Slate
Mods Done: UpRev, Bilstein 5100s in front, PRG 2" rear spaces, R1 Premium Drilled & Slotted Rotors, PosiQuite pads, Volant GenII CAI, 8K HID Lows, LEDs by ArmaDen, 3k HID Fogs, and Delete middle row console.
Mods in progress: JBA LT, PRT 300-cell hi-flo cat'd b-pipes, Borla xlr-1 muffler w/custom tubing, LED Engine Bay LEDs, Custom Suspension Lift by PRG, Custom PRG front & rear shocks, Custom PRG Rear springs.
Mods in contemplation: GoodHood or custom hood, Steel front and rear bumpers, upgraded front springs, Custom roof rack and cargo basket, Additional lighting.