Unforunately, it will be at least a week before I can even try to solve the mystery. The coolant overflow tank looks like clean antifreeze (green or yellow, I do not recall). If 2 quarts were sucked into the cooler lines I would think you would see it in the overflow???

If a defective vacuum modulator was causing ATF to be drawn by engine vacuum into the intake manifoldcI would expect to see lots of white smoke, almost like steam, from the exhaust. AT least this is what happens on a gasser. I do not see any smoke at all from the tailpipe. Also, in many cases a bad vac modulator results in bad shifting and she was shifting very nicely.

My 100 mile trip was on the highway so I would not have noticed a trail if there was one. I did notice that engine is essentially off the right motor mount. One theory is that this would misalign the rear drive shaft causing a leak at the seal, mostly while in motion. I hope that theory proves true since a rear diveshaft seal is an easy fix and I ordered new motor mounts.

I am not rejecting the theory. Just trying to talk myself out of anything that requires removing or rebuilding the tranny!!! I will sure be happy if I do discover a leaky cooler hose!!