I did some more research and have found a drop shackle that lowers 2,3, or 4 inches. I know the 4 inch setting will be to much and will slam into the under side of the bed. I can cut the ends of the shackle off that has the 4 inch adjustment as it will be to long. I have measured mine and I have enough room to fit a longer shackle as long as I trim the metal seem that sticks down from the bed. All I want is a 3 inch drop from a shackle and if needed I can take my block out from under the leafs and get another inch, so I get a 4 inch drop for about $125. The shackles are from JPL and they are actually from a lightning but they have the same width leafs as my truck. I have a 2007 Screw FX2. Has anyone done this or anything like it? Anyone see any potential problems?

 

Ive never heard of a shackle dropping f150 four inches unless you take out the factory block and use the 2 inch longer shackle to make it 4 inches

 

Supposedly the JLP drop shackles can do 2,3 or 4 inch drop. We will see. If they don't work out, I will return them.