A limited slip diff is basically brakes on the spider gears that don't fully stop the gears from turning. You get alot of drag on the spider gears that don't completely stop turning when working the way they are suppose too. With that said, when the diff part is together in your 2500, there is a certain amount of clearance between the gearing inside the diff. Maybe cram some leather washers in there, or rubber washers, or plastic washers in there. To act like a brake for these gears, to put drag on the spinning of the diff gears without damaging them. I would think this idea would last for a while but would eventually require maintenance on replacing whatever you use for the material.