Thanks for the tips on the springs. Calipers did not have them installed when I pulled the pads, so I didn't install them but I still have them. That seemed the most reasonable location for them, but I thought they might have been meant for a different application.

I did a little more sleuthing and the sound seemed to be more of a higher-pitched tinny type of noise that was constant and increased with speed. Pulled the tires again and got under the vehicle while my daughter rotated the rotors and I saw that the shields on both sides had been pulled in towards the back of the rotors...probably during disassembly...and were dragging on the back of the rotors. A little bending out with the pliers and we are all good to go. Thanks for giving me some things to think about. Now I'm thinking I may have replaced the calipers and hoses for no real reason, but 180k and my daughter driving the vehicle is probably good enough reason to spend the small amount of extra money on making that front end bullet proof.