Vibration under power at 55-60mph+ ?

[H_Cubed]

I have an '06 Lux with the suspension package. 25k miles. I recently installed the Coginito shocks and cranked the TB up to take the rake out. Starting height was 22.5", after 6 turns it was up to just a little under 24.0". I had it aligned.

I have never had any issues with strange sounds or vibration that I was aware of. At low speeds there's nothing noticebly different. Now however, at speeds on the highway, and under power, theres some vibration being felt through the steering and the floor boards. Once you remove your foot and coast the vibration goes away. If the vibration continued while coasting I may have suspected that the tires needed to be rotated/balanced.

Is this something others have experienced after doing a similar mod? Is this indicative potentially of some bigger problem like a CV joint going or a diff/transmission problem?