Cast Iron FMX shifting problem

Had a trans fluid leak, but tranny shifting fine. Now leak solved (new seals around linkage shaft) but trans goes from 1st, only couple seconds in intermediate, then third. 351 Cleveland 2bl, downshift rod disconnected because it was a couple inches too short to cause a full throttle kickdown. Trans engages in intermediate when you use the shifter. Don't seem to be vacuum leaks, though the hose to the modulator was kinked a bit (now seems ok). Should I try changing the screw setting in the modulator? Thanks:shakehead