Transmission question.

[Jalopy Tin]

Hi,
I have my transmission laying on the work bench as in the picture. Is it possible to turn the drums clockwise and couterclockwise by hands?
If not, what can be wrong?
Is it only possible if the clutch spring is released maybe? How deep shall the screw in each clutch finger be screwed down? I read about a play 13/16", somewhere, but i cant figure out were to measure.
Everything else is disassembled so maybe i should do the transmission too. I would be sad if i bolted all together and the transmission still is stuck.
Please, guide me further.
/Tom