RESOLUTION!!
Well, I discovered that the sensor I replaced the first time was actually the Vehicle Spped Sensor (VSS) and not the Output Speed Sensor (OSS). I dropped the pan, changed the filter, replaced the OSS, added a few quarts of ATF+3, then flushed the tranny by disconnecting the transmission return line and draining into a bucket while adding new ATF+3 fluid until I noticed a difference in the color of the fluid. I wanted to make sure I completely drained the old fluid out (including torque converter, cooler, etc.) in case the previous owner had used Dexron/Mercron III. Filled to the proper level and test drove. No more erradic shifting!! I don't know if it was the fluid or the sensor, but I would definitely lean toward the sensor. $50 including fluid, filter, sensor, gasket. Sweet!
I was so excited I went ahead and replaced the front rotors and pads!
Tomorrow will be fluid drain/fill on the differentials, checking motor compression, changing spark plugs, andmaybe flushing coolant system if I get really bored!
Thanks for the help and suggestions. Upcoming projects are rear drum/disc swap, FIPK, headers (anyone know where I can get them cheap??), and maybe a lift (front-->rear coil spring swap), larger tires, and ring/pinion swap to 3.73 (or possibly 4.11). Keep the suggestions coming!
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