I am looking to add more leaf springs on my 2003 F150 Supercrew 5.4 Lariat FX4. What i want to do is add more so the back end wont go down as much as it does when i haul or tow. I want it just alittle more stiff. On the other hand i dont want to make it too stiff because i do go offroading and i want it to be able to still be able flex. and ride close to the same as it does now. How may leafs are you all adding to your f150s? Also would i be able to throw something out of alighn if i put too many leafs in the back cause it will lift it up alittle? One more question how many leafs are on a 2003 7700 package f150?

 

Without making your ride unbelievably stiff, I would recommend only adding one. It makes it noticably stiffer of a ride, but in my opinion adding two or more would make it essentially a "hard-tail" on the road, which is never good.

This truck, I decided to go with airbags instead of an extra leaf, that way you can control how stiff you need it, when you need it. At least where I live, an airbag kit installed is only about $80 more than the add-a-leaf kit installed.

Also be careful with putting too many leafs in then hauling something that is way too heavy; half ton frames can bend/twist. As an example of how easily they can twist, I wanted to get overload leafs put in my truck, but if and when i put something in that would make the overloads get used, it would twist my frame (according to several suspension guys anyways).

(edited...) Oh yea, and no, you won't throw anything out of alignment by adding a leaf. Unless you re-arc them into "u" shapes, that little bit of lift won't make a difference. With my airbags, I can adjust my ride height on my 4x4 almost 4".

Hope this helps somewhat
Tanner

 

I'd do an add a leaf and put on airbags. The add a leaf will give you a little extra height, along with a little stiffness. The airbags will only be stiff when you inflate them.

 

I agree.