Hi Doug,
I think I can provide some insight on addressing the condition you are dealing with as our 2007 model 2350 once had the same condition.
Our tail was lower than the front by a noticeable amount. Our 2007 E350's front coil springs were originally over-rated for the actual load that our front suspension bears. I had learned that our 2007 Super Duty E350 was built with the same front coil springs as an E450 chassis of the same model year which raised the front noticeably high. The ride up front was also harsh, more than what we considered reasonable.
I simply went with the next rated spring "lower", an effort at being conservative with the modification. It was a gamble that worked out very nicely. You can read all about the project by
CLICKING HERE. Included are many pictures.
One thing is certain.... you are on the right track in your thinking. Once completed (don't forget a wheel alignment), you and your rig will both appreciate the reduced thrashing.