My Jeep immediately sagged 3/4" when I added a metal bumper and winch. A spacer would just be a "band aid" for a sag. To "fix" a sag you need new springs (the shocks won't help with a sag - I still have my stock shocks, but new springs with no sag).
2008 Rubicon - 2 Door - Flame Red - Automatic - MyGIG - Power Group - Deep Tint.
AEV Pintlers, BFG KM2s 35x12.50x17, Bulldog Fab Stubby Bump, Currie F/R Adj Trac Bars, Daystar Upper Dash, FireStik FireFly antenna, Kilby Rear Shock Skids, LoD Sig Stubby Bump, Midland 75-822 CB, Mopar Filler Door & Locking Gas Cap, Rancho LCA Skids, Rancho Oil Pan Armor, Riddler Diff Covers, custom Rubi Sliders, Sylvania X-treme Headlights, TeraFlex 2.5" Spring Lift, Warn PowerPlant HD, Woods Evap Can Relo, Woods SS Relo, Yukon 5.38s