I've been looking high and low on wheel vibrations and thumping and even death wobble..

I've got a 1994 XJ sport with rustys 4.5 lift w/ leaf springs, rustys steering stabilizer and rustys track bar. Jks quick disconnects.. I got an alignment right away after i did the lift, and never noticed any thumping or wobbling with 32s and crappyused rims..

I recently moved to Nevada and I threw the stock wheels back on forthr trip down and when I hit oh 65ish I noticed the front passenger side wheel kind if thumping.. It doesnt affect the steering or drivability, but there is a slight vibration and you can feel it in the steering wheel but only slightly.
My thoughts were that the stock tire was just out of balance..

Well I got brand new 33" BFG MTRs on brand pro comp 51s and got another alight net right away..

After that I hit 30 and feel a tiny little thumping and goes away immediately.. And when I hit anywhere above 70 the thumping comes back and stays. Nothing is wrong with steering and it handles perfectly.. I do feel/hear a bit of a humming when I'm in OD doing about 55 going up hill..

I don't think it has anything to do with the steering, but I could be absolutely wrong.. And it's not like any of the "death wobble" videos or stories I've seen/read.. I was thinking maybe its the hub/bearing assembly.. Any ideas don't want to just start replacing parts that don't need to be lol.. Any input helps thanks for taking your time to read and post!,