I actually have a Ford Lightning but my dad just bought a 2004 F-150 Lariat and it has the obvious rake to it. I measured and the back in 3 inches higher at the fender from the front. Is there anyone making shackles for the new F-150. If so, Is it a 2 or 3 inch shackle? OK, now here is my main concern, if you put on shackles to drop the rear end to level it out,...How does it affect the ride? I really do not want to hurt the ride, This is a concern of mine. If it does affect it...How much? Is it really noticeable? One last thing...How much are the shackles and were can I purchase them from?

 

I used 2" shackles on my 01 screw and the ride stiffened up a bit but not bad, also you will need to make sure drive line is within specs. if not you might need 2 degree shims to avoid driveline vibration. i got mine from summit racing

 

The factory builds the trucks with the rear end intentionally higher than the front so when a load is put in the bed, it will ride fairly level instead of going down the road with it's nose in the air. I'm sorry, but I just fail to see the logic in wanting to lower the rear end. It's supposed to be that way. The engineers at Ford aren't all without some sort of brain.
If I offended anyone, my apologies, but it's a truck.

 

I have a 2001 Supercrew and I lowered the rear with a 2" shackle. For me it leveled out the appearance and it did not affect the ride at all.

I later installed a Belltech 4" rear and 2" front suspension kit.

The ride improved dramatically! It is actually less bumpy than stock but more more responsive! I love it..

But you should notice no difference with the 2" shackle..the truck will look better.

Good luck