It had the dreaded harmonic drumming vibration at 60+ mph. So I first checked pinion angles. The rear pinion angle was out by 7. Thought that would be it, nope. Adjusted to within approx 1. Felt vibrations lessened, but harmonic remained. So I removed rear then front and drove without each. Problem went away when front was removed. I found the front was out by a lot. Adjusted pinion up until vibe stopped. It is within 2* of DS angle. Still have a slight vibration above 65, but not a harmonic pulsing mind numbing vibration.
That’s when I discovered the whole track bar interference and read how to properly set bump stops. Had the front set pretty close.
While fighting a stiff steering issue, the term “scrub radius” was explained to me. Due to haveing 3.75 back spaces wheels and 1-1/4 wheel spacers my scrub radius was very excessive. I removed the spacers and now I can turn with my locket engaged. So at this point I decided it was a good time to revised my front bump stops due to tires being moved in. So I rechecked my front and have it set. Once I raise my front upper shock mounts 1” I will be using 100% of my rancho 999255 fronts.