I did the opposite...
My springs were shot, so I installed new ones. The auto parts store, without my knowledge, sold me the heavy duty ones. That raised the front end really high. Since I planned to lower it eventually, I was quite unhappy. It took me a year of waiting for the springs to "settle in" before I decided something was wrong.
That was when I did some research, and found I had been sold the heavy duty springs. After a little arguing with the store manager (She sold me the HD ones because they stock them, but have to order the standard ones. She never told me I had a choice...), she ordered the stock ones. Since then I have installed the Western Chassis drop spindles, and went from your "after" look to your "before" look.
Here is a pic of my truck with the HD springs sittling next to Gerardo's (gchemist):
Slonaker