A friend of mine who is pretty much not brand biased was wanting a SD CC. It has to be a single rear wheel truck but he doesn't like what FOURWHEELER found, that axles in the Dana 50 on the F350 SRW trucks were tapered down to a diameter tha same size of the axles in a Dana 44. So I told him to order a Dually with the "Box Delete" option and get a SRW bed and put on it. He was gonna get new wheels and tires anyway so I thought what the hell it's worth checking out.
I grabbed my tape measure and we went to the Ford dealership and started measuring the differences between the insides of the rotors on both the Duallies and the SRW. what we found was that the dually PSD has a 2 inch narrower rear than the SRW. My friend said that it wouldn't work, but I told him that it would because Chevrolet has been running a 2 inch narrower rear on their 4x4's for years and Ford has always seemed to run the same width axles front and rear. He's still pesimistic about it but wer're gonna do some more research on it.
As far as the Ram goes I've never found anyone that wanted to convert a Ram dually since the 2500HD has the same diffs. I have heard of some putting the 3500 rear springs on a 2500.