2000 4runner vibration after lift

Hello everyone,
I just installed a Rough Country 3" lift on my daughters 4runner I now have a bad vibration when I hit 65 the goes away around 77-80. I really cant tell where it is, seem the whole truck vibrates but not in the steering wheel or pedals. The only thing I can think of is the drive shaft angle was changed due to the lift and maybe its a bad u-joint.

Any thoughts any input appreciated
Thank you
Otto

 

Have you checked your engine mounts

 

I did the diff drop. Problem solved

 

Whats a diff drop?

 

I was going to say that or check the U-Joints. Those are the most common issues after a lift in them.

 

The front IFS differential, sometimes you have to drop it down a bit to prevent binding.

 

I was going to suggest an alignment also, but looks like it got squared away