types of leaf springs?
 

im not sure where this would go so ill put it in here i got a new truck and i noticed the leaf springs are diff from the rest of my fords i have had im not sure the technical diffrence but in my opinion i like the looks off one better than the other and i think it rides a lil more smoother than the other. so here it is the first one is a 2002 f350 crew cab short bed 4x4 off road xlt 7.3l diesel (the one i like the looks and feel of) the second is a 2003 crew cab short bed f350 lariat 7.3l diesel 4x4....not the off road package. so really im asking what they do this for and if it can be converted to the style of the 02 sorry if its confusing
also i noticed the first one (the 02) has an extra leaf spring so again ima ask why. thank you so much for the help.

The first picture has an overload spring on the top for extra load capacity. It's usually an option that goes with a trailer or camper package. If you use your truck, it's a good thing to have.