99 cherokee vibrations

I lifted my jeep with a rustys 3" and got some bad vibes so now Ive installed a hack and tap and 6 degree shims took care of lower speed vibes but at 60mph they start back up, I removed rear drive shaft and its a smooth ride. Installed new u-joints and it still vibes at 60mph plus. Not sure where to go from here!!

Thanks naxja I got it

That left a little to be desired in the area of information. Got anything else?