not sure if terminology correct but i'll try. steering wheel straight and tight. turns fine. steering feels better at highway speeds. at lower speeds 25-45 on bumpy or roads with a lot of crown feels like i'm driving a boat at times. feel like road controlling jeep. didnt feel anything like this before lift and tires
Got it... First I want to answer a question you asked that I missed. You should have caster somewhere near 4.0° to 4.5° with that set up. It could be a little higher, but too much and you are over working the drive shaft.
The high steer in the Rubicon Express kit is the proper drag link flip with front track bar bracket... It requires them to drill the knuckle to install.
What you are describing, very well could be bump steer... Which is exactly what the high steer is designed to eliminate. When you hit a bump and the suspension moves, the Jeep tracks to one side or the other.
Now, this gets me thinking... If they put on the front track bar bracket without the drag link flip, it would likely be worse. Those 2 pieces go hand in hand. Can you take a photo of your front axle for us to examine?