If you are able to get the f*od springs at a great deal I would think as long as the measure out the same and are stacked (packed) the same and the ends will bolt up you should be OK? I'd be certain to check the unloaded height from the pin to the top of line between the front and back mounting holes and compare with yours. Also the GVW of both trucks.
I'm sure someone else who's considered this swap or done it in the past will chime in shortly. That's what I'd look for if I couldn't find a matching set off another Ram.