dogyard,
I am very happy to read that you made a significant difference in the ride of your E450/2350.
Just for reference, here is my 2007 E350 with an 11,500 GVWR, 158" wheel base and an over-all length of 23'-8". At a glance, you can see the entire house of model 2350 rests on the rear axle. I also noted the "big-hitters" of our load. Because of the spare tire and fresh water tank in the far back, the teeter-totter effect is notable as seen in the picture. The front end is slightly lifted. Our front axle is under-loaded while the rear axle is at it's limit, once being a little over the GAWR limit. The actual weight numbers are taken from a truck scale.
As I previously mentioned, I will soon experiment replacing my E350 front coil springs with lower-rated ones with hopes to lower the front a bit to level the rig, along with providing a softer ride up front. I am trying E150 front coil springs because as seen in the diagram, the front axle isn't carrying much of anything at all. It carries less than an E150 van front axle GAWR.
Many people don't realize that the E350 and the E450 have the same front GAWR. All of the difference in load is related to the rear leaf springs and the thicker frame of the E450 chassis to carry it. The front suspension including the front coil springs are identical between the E350 Super-Duty chassis and E450 chassis. So my stock E350 front suspension offers a rougher ride than you with longer PCs that place more weight on the front suspension.
