Can I break in motor with no driveshaft??

Dumb question here guys but can I break in a motor with no driveshaft :dontknow:
383 in a notchback with 4-speed conversion and I just have a yoke in the end of the tranny so it doesn't leak fluid. But as I was turning over the motor the yoke is turning. Should this be happening and will it not fly out if I try and fire the motor :help::help: