Correct, once the nut is loosened and the screw is loose, the dist. comes straight up/out. Sometimes when it has sat for a very long time the distributer rusts to the head, and sometimes the distributor shaft/shaft cavity/cavity will rust together.
If you are not careful, it is possible to wreck/crack the metal distributor housing. The distributor design has a keyed 2 piece shaft. Part of the shaft comes out with the dist. the other part stays in the motor. The 2 shafts are keyed so they can only be put in the correct way. However there were aftermarket distributors that were a one piece shaft, no 2 piece.
Here is puller/tool, it threads into the dist. shaft cam screw hole, to pull the dist. via the dist. shaft.
https://www.brattons.com/distributor-puller.html
Here is a previous post/string with tips/hints
https://www.fordbarn.com/forum/showt...tributor+stuck