When you do get it in gear, how far off the floor do you have to let the pedal come before the clutch engages (car wants to move)?
Does this distance ever change say with the engine/tranny hot or cold?
Does the amount of freeplay travel in the pedal ever change?
Does this noise occur when lightly pressing on the pedal, or when the pedal is at full travel (clutch disengaged), or both?
It sounds like the clutch isn't fully disengaging which is why it's hard to get into gear. Most noticeable in reverse because of the lack of synchronizers in reverse. This can be caused by most anything in the clutch assembly. If I remember right that year of Fords still had a manual adjustment in the clutch pedal. You had to pull up on the clutch pedal periodically and the pedal assembly would self adjust the freeplay. Make sure if equipped, that this mechanism isn't causing the problem by not allowing enough travel to fully disengage the clutch. Should be no more than an inch or so of freeplay in the pedal.
It sounds like clutch time.