Is the CHK SUSP light on? If not, leave it alone. This is a love hate thing here. I have it my 2000 and I will maintain it and fix it when it needs it. It's part of the truck. I have read a few posts about others who have converted to coils/shocks and they are not happy with the difference. Well that was a bunch of money wasted on nothing. It will ultimately be up to you and what your preference is. If the light is off, drive it and enjoy it. Save your money for other problems that will come up. Check out Suspension, Air Suspension, Parts, Conversion, Kits, Air Ride, Airbags, Shocks, Coils, Buick, Cadillac, Chevrolet, Chrysler, Ford, Hummer, Range Rover, Lexus, Lincoln, Mercury, Oldsmobile, Pontiac, Toyota, AirLift - Suncore Industries. for any parts or a conversion.
I have been looking for specs on what the height is supposed to be so I can get an idea of mine is sagging.. Mine does the same from time to time but it's ok and doesn't effect the ride. I haven't found the measurements yet for what is acceptable. Might have to find out from Ford.