Thoughts on vibration
One more thought to go with tire/brake suggestions. Since the entire thing was apart would it be possible a rock or small amount of dirt got between rotor/drum and the axle when reassembly occurred. Also between brake and wheel. Should be able to check this fairly easy with car on stands rotate tires and check sidewall clearance between a known fixed point. Mite not be much 1/8 in or less but at speed could be an issue.