What size tire's are you running? Keep in mind that you will want the f350 front springs also even though you already have a lift. If you use the 350 main springs with the lift spring you have under the 250 springs now it will ride a little better. Also a Dana 60 is going to lift the front of your truck almost 2 more inches. 4.10 gears are a lot easier to find especially when it comes to F350 4x4s