They will level out the rear of your truck, I had them for alittle bit, but hated filling them with air. But yes they will level out the back of your truck. I think I got mine at Pepboys or something but Im sure any auto parts store will have them.
If you want a good pair go to AutoZone. there around $50 bucks. I have those on for now intill I get mine lowered. There called high jackers. I have mine hooked up to a air compressor and a dual feed switch. So I dont have to put air in them all the time.