Bad thrust bearing?

I built a 360 years ago. PO had used NOS on the motor. I never checked or looked at the crank, something I never do. Anyway machine shop didn't catch it either. First time I ran it and put the timing light on it, the damper moved in and out under throttle. Turns out bearings were fine, crank was wiped out. So don't just assume you can change the bearing, because if the crank is bad, bearing won't fix the problem.