The Kings will work fine with the factory springs, though if you're not really pushing your truck off-road, and 2.5 shock is arguably overkill. We have not tried out King's shocks or coilovers personally yet, but in theory, they should be a little softer on the street than ICON, though they will have a slightly stiffer ride than the factory shocks or a set of stock replacements like the 5100s.