Why the shaking

[dsvw]

Hi,
2013 G37X 4 door.
114K miles.
My car has a slight shaking issue in the steering wheel between 70-75mph
It is super smooth at all speeds lower than 75

The tires are new and I have had them balanced twice within the first 1k miles of use.
New tie rods
Complete alignment
Tire pressure equal at 33psi
All the suspension boots are free of cracks.
The Ball joints are tight
New Upper control arms
I looked at the sway bar links and they appear to be good, no movement no noise.

Any ideas?
The only thing I can think of is a bad strut?
Does this car have a steering dampener?

Thanks.