We like this kit. I like it far better than the Firestone kit as the bags are a smaller diameter and will not be harsh or bouncy like the bigger bags in the FS kit. This kit also sits on top of the leaf packs and will help reduce sway. Also, no mater what lift blocks you have, as long as the springs are in the stock position, these will go right on. They do require a few holes be drilled in the side of the frame...or you can weld the brackets on...only a few small welds will be required and the brackets can be removed if need be. Yes, these work on all year Titans and 2 or 4wd and off-road/p4x models. These typically run between 10-40 psi for any loads you would be able to safely carry in a Titan, and the bags can be filled with a compressor or even a bicycle pump withjust a handful of strokes. Plumbing seems to scare a few people, but I assure you its easy as pie. all the current bag kits use air-brake hose and fittings....you simply push the hose in the fitting and you are good to go...no threads or glue and the hose is easily removed if need be. Below is the stuff from Airlifts site...blah, blah, blah
Air Lift
Air adjust ability makes the difference. Steel factory suspensions must find some type of happy ground between ride comfort and load hauling capacity. The problem with solving problems with steel springs is that smooth riding suspensions have trouble with heavy loads, and heavy duty springs ride rough. With Air Lift adjustable air springs, you can have the best of both worlds and solve your suspension problems by tuning your air bags to handle all load and road conditions. To give the air helper springs more support while towing or hauling, increase the air pressure, and then remove the air for a softer ride while your vehicle is unloaded.
Some of the common load and hauling problems and air lift air spring can solve are…
Suspension Sag - By adjusting the air helper springs to accept the tongue weight of the trailer, proper weight distribution to all tires can improve steering, braking, and tire wear. This process becomes increasingly important while towing.
Rough Ride - With Air Lift's progressive spring rate, and adjustable air spring design, a smooth ride is provided while the springs absorb bumps, keeping the vehicle on the road for better handling as well.
Bottoming Out - Air Lift air springs can also help with the ride height problems you may experience while towing. Many times, when hauling or towing, your vehicle may sink, or bottom out, providing an unlevel riding condition. Air Lift springs can be used to restore a normal ride height, reducing wear on your suspension and eliminating the crashing and bottoming out on bumps and holes.
Sway and Body Roll - If you are looking for a safer, sturdier, and more comfortable ride, Air Lift air springs are the solution. When you are towing your camper, trailer, or boat you can use the air springs to precisely adjust vehicle height and load support, allowing for exact alignment and eliminating trailer sway. The air helper springs increase spring rate, support, and vastly improve vehicle stability, while virtually eliminating roll and sway.
Headlight Aim - The only way you have proper headlight aiming for safety is by having a level vehicle. The stability that will be provided by an Air Lift air helper spring, will make for a level vehicle and safe driving at night.