I've been watching this thread and I don't think you have a real unique issue. I know, it's easy for me to say, right??? I agree that a real good experienced automatic transmission mechanic, can figure this out and correct it. That's what I would do. Have him look at it. I have a similar problem, not identical, to yours with my '71 GTO TH400. Mine likes to upshift quite quickly from 1st to 2nd. It won't downshift again to 1st without being almost completely stopped. If driving in the 1st gear range, with it in 2nd gear, I have to really mash the pedal to get it to kick down to 1st gear. I have the factory electrical kickdown switch on the gas pedal. I tried making some adjustments with springs and other things, not successful, so I gave up on it. I might take my own advice and seek out a transmission mechanic. The car as a whole operates just fine. But, this transmission issue is irritating, Nicholas.