Wiper motor swap

Look closely at the 2 pics in post #5... notice the shaft that pitman arm bolts to is off center in one brand/type of motor. That's where/why the offset bushing is required. The bushing doesn't turn in the arm so we shouldn't consider it eccentric, just offset.
Since the rectangle of the pitman shafts also different, correct pitman arm and bushing for each motor is req'd. Wiper travel wouldn't change.