Like Clyde said do the front spindles then add air bags to the back, the rear bags are not much more expensive than new rear springs and they are adjustable........you can get the stance you want by just adjusting the bags instead of changing the springs.
BEFORE:
http://kieth.smugmug.com/Trucks/66-G...9351&k=Vp3C3v3
AFTER:
http://kieth.smugmug.com/Trucks/66-G...5607&k=8gdB29n
