First what I know. 67 was the last year for all bronze bushings in the linkage ( except for pitman arm bushing they are all plastic ). 68 and 9 have black plastic bushings in the linkage.
Now about the pitman arm bushings and what I think I know. A basic 2 speed motor has its output shaft centered. The black bushing there are also centered.
A 3 speed motor has its output shaft offset. So rather than produce 2 different pitman arms and/or linkages to correct wiper throw/travel they produced a offset bushing.
Take one of black and the white apart and prove me right or wrong.
