pappawheely
Autonomous4X4
What you are describing sounds like what is known as Death Wobble. That is completely different that tire balance vibration. Death Wobble is akin to a loose wheel on the front of a bicycle. Most Death Wobble causes are from loose or worn steering components even poor caster alignment. Most rather than finding the root cause, will use steering stabilizers sometimes even multiple stabilizers to control it. Stabilizers are just a bandaid for the problem in my opinion.
It could be a lot of things but I agree it sounds like death wobble. Is it independent front end or straight axle? When you lift trucks and put big heavy tires on it you need to upgrade your steering linkage. New parts work for a while but they usually wear prematurely. Centramatics work well for balancing the tires but if you get past a certain diameter and the tires are worn you will get some imbalance. They can only do so much. My 37's on a 17 inch rim are over what they recommend. When my tires were new, they were smooth as silk. Once the tires got some chunks out of them and some mud packed in the wheels you can feel some vibration. I think 35's would be much better.