Anybody know the easiest way to lower the back of a 2004 F-150 2 to 3 inches?

 

Not yet.

 

i say shackles

 

Yep, I think shackles would be the way to go but Ford doesn't make them so they'd have to be after market and I haven't found anyone who offers them for the 04's.

 

Have springs dearched

 

I might just order a new set of stock shackles, take them to a shop and cut them apart and have a piece of c-channel welded in, making them 3.5" longer. That looks to be the longest we can get away with before it hits the bed. So it would lower the rear 1.75", almost making it level.