I made a rambling, self-serving, and partially incoherent thread a few weeks ago about my experience with both Firestone Ride Rites as well as Air Lift 5000s for our 2008 Ram 1500.
The first kit, the Ride Rites, had parts that were fabricated by a buffoon and wouldn't fit. So I went with the Air Lift 5000s and also bought their Wireless Air compressor kit. I got the right kit for the truck, per their website. Went to install it and the brackets did not fit on the frame. Spent several days of sporadic email communication with the company asking for them to explain whether they had sold me the wrong kit or if they had fabricated it incorrectly. Allegedly, their engineer got around to looking at my photos, and then they told me that it just didn't fit the truck and that I should switch to their lesser product that mounts on the leaf springs, carries a lower rating, and is only recommended for occasional use. No effort to arrange for the return of the kit, give me a slight refund on the compressor kit, or even to help cover the cost of their lesser kit. Just "the kit we say fits your truck doesn't fit it, so we will just say sorry about all your wasted time and too bad, buy our other product". So because of a now short time constraint due to the 2.5 weeks of wasted time on the first two kits, I had to go back to the Ride Rites, which I knew would fit at least if they sent me a kit that was made properly. Which they did, and they installed just fine.
So I would recommend staying away from Air Lift products. The compressor kit has worked fine for the 1.5 weeks it has been installed, but I wasn't big on their handling of their air bags not fitting what they market it to fit and the waste of time it caused me. I would put money on it that they never advise consumers that their kit does not fit the 2008 Ram 1500.
The Ride Rites work just fine as long as they don't let the buffoon do the metal bending on the brackets. We have not load tested the bags yet.