Cab vibe issues

Chasing down some vibe issues in the cab .. shakes vigorously 40-70mph. Heres what ive done to help correct this issue but its still there..

Mods: billstein 5100's
285/75/17
17x9-38

Maintenance to correct vibes:
Lower ball joins, outter tie rods, inner tie rods, steering rack, alignment, new carrier bearing, carrier bearing drop kip, tire balance (twice), greased the drive shaft,

What else should i do? Looking to replace my transmission mount and the rear axel shims. What shims should i try? Pretty expensive to try all the available sizes.

 

Is the vibe consistent? Vibe nonstop between 40 and 70?

Check front and rear wheel bearing for play. Do the same for the ujoint.

 

Have you noticed whether it goes away in 4x4?

It’s not uncommon for the drivers side needle bearing in the front diff to go out. Any excessive play between the inner cv housing and the diff? Does putting your truck in 4x4 make any differences?

this device really helped me with tracking down vibration issues with my truck.

STEELMAN 60635 Wireless ChassisEAR Diagnostic Device Kit

https://www.amazon.com/Steelman-606...gbOj&pd_rd_i=B07K3XZR7R&ref_=pd_bap_m_rp_1_sc

 

Upper Control Arms still stock? Might want to start there.

Perhaps something else to add to the 'To-Do' list,
https://www.energysuspensionparts.com/8.4107

 

What are the Cab Mount bushings like?

What sort of mileage are you dealing with?

Is this on every road when you are at that speed?

How do the tires look ?? Do the people doing the balancing know what they are doing ?

I have seen tire techs get one lug super tight the air pressure drops causing the wheels to be off enough even the best balance does no good.