I have a 2009 Sierra GMC 1500 SLT Extracab with about 30,000 easy miles. I added a 1" front leveling kit so the my 285/18's would clear the mud flaps and my truck always had a sag in the rear. I often haul dirt bikes, ATV's, and sleds in the bed, and tow a 4500lb camper on occasion. I'd like to maintain the same ride quality but get the rear 1"-3" higher even w/out a load. Main question I can't seem to find an answer to is will any of the airbag type leveling kits provide any lift? I'd be happy as long as I can get about 1" without compromising the ride much. My springs may have sagged a little but generally the toys are only in the back the day I'm playing so the truck isn't loaded continuously. If the airbags can't provide lift, only level when loaded what would you recommend? Truck has 2 main leaf's and noticed the helper leaf is about 1/2" from the mains unloaded. Once I put a 250lb dirt bike and gear in they the "stock" helper leaf pads are just about touching the main leaf. My fear with "add a leaf" (don't know if they install under or over the helper leaf) is that it will put force the helper leaf to into the mains and then I'd have 4 leafs working and a stiff ride if that makes any sense. I could just buy/add 2" blocks and go that route but I'd really like to add a little capacity as well. My camper is just a "Trail-lite" 21' but it probably has 600lb of tongue wait so when you throw an ATV into the bed also it's over 1,000lbs and I swear the rear has sagged over 6". I've read hundreds of posts but can't seem to find out if air-lift/ride-rite or similar airbags will provide any lift verses just leveling under load. Thanks, The Rocker!