8-3/4 PINION SLOP

I'm looking at a complete A-body 8-3/4 rear at a fantastic low price. 741 case, 3:55 SG cone type
Problem is I can grab the yoke and the pinion will move +/- 1/4 inch.
I'm guessing pinion bearing/seal is shot but what else could be wrong inside? Gears? bearings?
Never took one apart. Picking it up this Saturday and will be stored as a spare.
Thanks