[83GMCK2500]

Whenever I have seen that excessive wear one one side of a rotor surface and far less on the other surface the caliper was stuck or sticking in the bracket/slide. Also, incorrectly installed or incorrect pads in a caliper can bind and cause that. Not disagreeing with your statement about brake lines, Low Elco, just clarifying my observations. Hoses/lines are a too often overlooked part of the brake system.