I pulled the tranny apart again and checked all the thrust washers. Every one of them is .060" thick and perfect. I assume the reason all the thrust washer tang patterns are different is so that you can't mix them up. The only one I had any question about was #8 on the back of the rear planetary. The tangs on that washer don't fit into the round holes in the planetary (2 do and 2 fit into the long slots in the aluminum planetary frame itself). With that said, #8 thrust washer sits perfectly flat between the rear planetary and the one way clutch race. The bottom needle bearing shell(open three piece design) is in perfect position with the bottom half (round end down) pointing up. The needle bearing itself sits in the bottom shell and the top half points up where it fits into the bottom of the planetary. The upper needle bearing shell and the bearing itself is sitting in the top of the rear planetary and has never been removed. The top shell of that bearing is facing up where it contacts the sun gear when everything is assembled.
All the clutch hubs are in position and perfectly seated into the clutch disks. The tabs of the reverse-high clutch fit down into the input shell slots with about 1/8 on either side of the tab.
With the pump bolts tight but not torqued and the thin black plastic selective washer behind the pump, everything turns and feels fine. I cannot detect any free play with a feeler gauge or my dial indicator.
So, what does this all mean? I had .30 end-play to start with (dial indicator and feeler gauge). My original selective pump washer was .078 thick and the plastic one is about .058. At this point, I have no end play. This means I've gained about .050" somewhere. There's nothing spongy and after 10 or so tries I can't see anything wrong or out of place. Is it possible the one way clutch race is not seated in the case? I took it out twice and made sure the oil feed hole was aligned correctly. The bolts holding it in torque down without incident. I thought I might have added an additional thrust washer, but I don't see where that's possible.