Thx for the info here too... yes it is good to support local business... too bad I didn't do it before I left.
Below is a quote from another fourm, which is good input for all of us. THX PJ
"As noted in another reply/post, you don't need airbags to add these. I have a Fox 1150 on a 2008 F450, and added the Stable Loads to level the rear a bit-- the SLs are higher/bigger than the factory bushings so the secondary spring picks up earlier as the camper weight is loaded. On the F450 with 14. 5K GCVW, even with a 5K camper, I'm far from the suspension stops-- but the SLs did raise the rear about an inch when I'm loaded for a long trip.
I did the installation in my driveway-- cut the factory rubber bushings off with a utility knife, bolted on the SLs-- a no-drill installation as advertised, about an hour (it as cold and miserable weather). They work as advertised as near as I can tell-- at least I'm level, have minimal sway, and don't porpoise when I hit bumps. With my just-departed Silverado 3500 DRW my seatbelt would lock up on some of the same roads. I tried the SLs as a first alternative to adding airbags for leveling-- turns out for this truck they're all I need. "