Input shaft end play

The transmission in my '85 300zx is on its way out, and the clutch died a few days ago. I have another transmission laying around, but I found it to have alot of end play. I cannot find a specification in the service manual or online. Does anyone have a generic spec for how much is too much?

Its a FS5W71C 5 speed manual.

If the shaft fits into a pilot bushing at the tip of the input shaft, the input shaft could probably have a bit of play in it without it being a problem since the pilot bushing will support that end of the input shaft. If it is stubby and stops right after the splines, then any play is a bad sign. Compare it to the one that is in there now.