1966 Ford Thunderbird failure to go into gear

Transmission problem
1966 Ford Thunderbird V8 Two Wheel Drive Automatic

restoring old t bird, transmission worked when I put car in garage. Slipped some. However. Now I start car move shifter into gear, linkage is connected, moves however car does not go into gear. Can shift from park to 1st and nothing happens. Car acts as if still in neutral.

linkage connection came off when I had to raise the motor however its hooked back up. Only transmission work was replacement of filter, fluid and gasket.

vaccum line from trans to carb is hooked up.
any idea on how to get it working?

possible fluid is low now but not sure if thats a factor.