Mike, I had this happen on a 47RE in a diesel truck one time. It turned out that it had broken the middle ring on the input shaft.
As I remember this middle ring seperates the rear clutch and converter lube circuit. When the ring is broken, the converter lube will actually apply the rear clutch. Normally this isn't a problem because the rear clutch is "on" in all forward gears.
But it can cause the vehicle to move forward in Neutral, and bind in Reverse.
Isn't this the ring that you damaged that I had Tiffany drop off to you? Maybe it is damaged again (or a mismatch of parts not allowing them to go together properly?)
The trans thats in the car is from the bone yard..
I changed the pump and input shaft and put a drain
plug/temp gauge on it... thats all I did so maybe
this thing was broke when I bought it... it just
looked decent inside... if I changed the pump and the
input shaft is in it... could I have broken that ring
but the pump did slide in nice.. I used pins to align it..
but this sounds lie how its acting
