The funny thing is my truck had 4 springs stock, instead of 3. Could this be because its a EGR model? At first I thought it already had a 4k kit (It didn't fell like it). I talked to Piers and they said that some came stock with 4 springs. Well, I drove the truck after the install of the 3k springs and I was impressed. I didn't really improve my power. The power is now distributed over a wider range. 
