Driveshaft won't fit
IIRC, the park rod has to go through a spring loaded dog in there. When the trans is shifted into park, the lock is activated and you are in park. In any other gear, the lock is deactivated, and the car is not in park. Just spit balling, but since the valve body was the only thing that you messed with, maybe that rod position is keeping it in park.......Just a suggestion.