Update…
It has an intermittent death shake now.
It is not a constantly occuring problem. It’ll drive perfectly smooth, then out of completely nowhere it’'ll shake like someone trying to shake a glass bottle of ketchup… It will do that for about 5-10 seconds, then stop shaking, except for a slight vibration.
Again, all this is ONLY 55-60MPH zone. Drive smooth as hell at lower speeds, and even faster than that.
It’s becoming a severe problem though. There is no play in any wheels or anything, and the violent shake came out of NOWHERE today.
Ideas so it’s not going to a shop blind and have them racking up a giant bill on diagnosis.
Edit- Also, just checked the tires, no excessive wear on any of them. Nothing abnormal.