Terrible rattle after brand new Old Man Emu leafs put on

So, I just finally got the correct dakar leaf springs on my truck (4 wheel parts had originally put ones on that were too long, and they were pretty stiff, now they are not stiff and feel as though they should be just right). These things are now the same size as stock, but now all of a sudden I have this pretty bad, disconcerting shake between about 10 and 25 mph and then again at 50-55 mph. I his not the engine or tanny or anything, this happens whether the gears are engaged or if I'm in neutral. It happened only after these springs got put on and it's pretty bad, the whole dash rattles and it's crazy loud. Before I call these guys AGAIN, any ideas?

 

x2 check out beefed tacos carrier bearing drop

 

Wow, yes. Give that man a cigar.

 

Well it actually would be slight lowered with springs that aren't so tight (which kind of sucks, but oh well), so a drop isn't the problem, I need to get under there and raise it or flip it.