I've built an "expedition XJ" for extended backcountry travel with a 3" OME HD leafs and springs and 3 oem coil isolators. With two isolators unloaded I was an inch high in back and I was getting bad deceleration vibes and a little bit of driveline clunking. With 3 isolators unloaded. I was perfectly level with just the teensiest bit of deceleration vibes. Now, loaded up with a roof tent and camping and recovery gear (pull pal & hil-ift) in the back, I'm sitting about 1 1/2"-2" lower in back. It looks a little silly, but the driveline is quiter than ever. Should I bother with removing a spring isolator or investing in an airbag system? That JCOS leveler thingy makes sense now.