Not sure if this has been brought up before, but I figured I would post a picture of the difference. I'm in the middle of installing my level kit on my 2012 and thought I would bring out the old springs and see if they where the same or not, 3rd gen came off my 2007, it is about 1" taller and has 7 coils vs 6 on the 4th gen, 3rd gen coil width is .825" and 4th gen is .808"

 

Probably a big part of the reason why the 4th gens ride so much better than the 3rd gens do. Also probably why my 2012 almost bottoms out on bigger dips and bumps on the highway

 

My previous truck was a 2003 Ram 3500 and I had to have the coil springs replaced because they was "sagging" to the point that the front end alignment could not be done. Then I had another coil sping to go bad after that. Keep in mind that I did not drive off road. All driving was on the highway. All the front end alignment guys said that the springs was just not able to stand up to the weight of the engine. Hopefully that has been fixed on the 4th generations. My thought is that the 4th gen coil springs need to be heavier/stiffer to handle the engine weight...

 

I dont know, It is definitely smaller than the third gen springs. So unless they are made from a different material???

 

So, with my airbags on the rear the front still sat a little lower even with the level lift, So I decided to pull the springs and try the 3rd Gen springs, Actually gave me another 3/4"-1" more. Looks level now to me. No ride quality difference except seems to not sway in corners when loaded as much, not that it did all that much before.

 

Interesting find. I have another thread where I wondered why the rear leaf pack on my new 3500 had fewer leafs than my '04.5 2500 too. I never put a caliper to the thickness but they looked the same thickness to me. My dad's '06 3500 has the same as my '04.5 2500 but one more short and fat overload. So technically he has two more leafs than my '12 3500.

Might be time for some rising rate coils with shocks in the front and some bags in the rear I guess. Not too cool to go backwards. I'm not sure who buys these trucks for the plush ride but they may be better off buying a half ton or a sedan perhaps.