Fluid Drive/Solenoid and Governor Problem

This is for the old timers in this group: Will replacing the solenoid and
governor on a 1949 Chrysler Windsor with Fluid Drive help it shift like it
is supposed to? All other things check out fine, the wiring and the fluid
level in the torque converter. The problem is: If I take my foot off the
gas pedal and let the transmission do its thing, a violent, loud clunk
occurs. If I push in the clutch, it merely clicks and shifts smoothly. Any
ideas about this? Also, sometimes the transmission does not downshift when
coming to a stop without me pushing the clutch in to force it to drop to
third from fourth. Am I on the right track with the solenoid/governor
problem? Any ideas would be appreciated.
TIA