hitting bottom

I dis the firestone airbags in my 31' coach. I was expecting a modest 3" ( hoping for 5"). What i actually got was about 1 1/2". Not a lot for the $500 and labor i spent. But they have kept me from dragging a fee places. The best clearance i got was flipping the trailer hitch over. That got me almost 6" at the bumper. What i have noticed now is the skids stick down about 3" lower than they need to. Since one died at a gas station they will both be getting re fabbed soon.
Imo the rollers actually decrease ground clearance and prob wont support the weight of your rig anyway.
Best bang for your buck is taller springs or re-arched springs and a new alignment.