Rough Country 3.5 lift 2nd Gen

I just had the Rough Country 3.5 lift installed on my 2007 Tundra Regular Cab Short Bed 4x4.
Upper control arms, swaybar drop, diff drop. Rolling on Micky Thompson 305/60/R18.
The ride is horrible! Extremely stiff, every bump is magnified and shakes the cab.
Is it possible the loaded struts were installed wrong? The instructions say the arrows at the top of the struts need to face outward, maybe they installed them backwards?
Does anyone else have this setup?

 

E load tires I assume, those alone make it ride firmer.
That is a high lift for suspension on a tundra, most run 2 or 2.5, 3 max....higher you go typically means firmer ride. At your height, suspension travel is limited so yes, it rides hard.
The lift manufacture is not known for smooth suspensions, thus the name

You might have some improvement- what tire pressure are you running? What load rating tire? Those tires may be 12 ply tires, if so they are F load...way too much for a half ton so they ride like bricks.