fromanhb said:It would be cheaper to buy a used 2500 with a cummins in it. Beefing up the axles would be one thing that needs to be done as well as the suspension components, most likely having to fabricate some brackets on the frame for suspension and/or the engine itself. You would also need to stiffen the frame in certain points to handle the extra weight for off-roading and such. Changing the entire fuel system/cooling system is also a must. It would cost much more to try to convert a 1500 to accept a cummins, then it would be to buy a used 2500.