[JoeFromPA]

No spacers. Rotors are ~10k miles old zimmerman cross-drilled

Shimmy can be as severe at 50mph as at 80mph, but seems to get a bit worse as speed increases above 85-90mph. But perhaps just more constant there. It's not linearly increasing with speed. When it's at its most severe, I'm guessing the steering wheel is shimmying through 5-7 degrees of motion. Like a really badly balanced tire or how the steering wheel will shake like crazy when a rotor is very warped during braking.

I'm gonna focus on bushings at this time. Off the top of my head, I'm thinking control arm bushings (most likely), steering rack bushings (less likely), sway bar bushings (least liklely). Any others? I'd include strut top hats except those should be brand new with the bilstein HDs....hmmm...