The frame has changed on the 2002 Ram 1500, also features independent front suspension. No plow prep package was offered this year for the half ton trucks.
For 2003 (production to start in Sept.) the "Heavy Duty" 2500 and 3500 Ram will keep the solid front axle but recieve a new frame, body, a new 345hp Hemi or a new, quiet, Cummins deisel (I saw them at Expo 2002 in Louisville).
I have spoke with a rep from BOSS who said they have the framework for both the "Heavy Duty" trucks (W/no offroad or sport packages) I did not ask about the framework for the half ton truck.
I would think if you can find a framework to fit the truck you would be in good shape as long as you dont overload the axle or springs.