I can tell you my 94 1 Ton with a *tow package* has 8 heavy leafs if that helps any? Mine may be heavier than stock. I put my pig of a slide in camper in mine and hitch a 20' boat and my bed lowers about 1.5" (2000# +/-) and its barely enough to get the rear shocks working just enough to avoid jarring your spleen up to your forehead on moderate size bumps/potholes?
With 1 ton springs I suspect youd have the same problems I do when unloaded and the back of your truck will come off the ground on big potholes and youll avoid some stretches of highway unless your an amusement park fan or have motion sickness pills handy. My 5 and 11 year old think its the best truck in the world because they bounce off the seat?