Just to add a little more smoke to the dumpster fire, from someone who was paying the rent and feeding his family by working on these things when they were nearly new- - - - -the heavy duty 3 speed Borg-Warner T-85 that was mostly used in Pontiacs was modified by B-W to make the original automotive 4 speed used in late 1950's muscle cars, the T-10 by moving the reverse components to the tailshaft housing, and adding an extra forward gear to the main case.
Jerry
