Add A Leaf?
i added supper stock springs to my dart and there was a noticeable difference from stock. the difference is 1 extra leaf so i guess it would be the same idea that you're talking about. it's supposed to be a 3 inch increase in height above stock. also keep in mind that if your springs are already "sprung" or worn out as mine were, you probably won't see that much of a difference. check my post from today titled "got the dart back" or do a search for my posts, you'll see photos in there from before and after. the car really did sag in the back and now it's a lot higher and the ride is a lot better too, a lot stiffer and not a lot of sway anymore. i would recommend just getting new springs, not just adding a leaf. search ebay for them, i got them from mcveighs truck springs (or something like that, their in ohio) and was really pleased with them. Hope this helps....