if its only 1/4" lacking, the splines have to be already engaged, unless the trans. isnt a match for the clutch/flywheel/engine. (because the splines are nearly 2" in engagement. maybe an issue with the throwout bearing running out of room against the clutch fingers; adjustment of the clutch freeplay on the linkage...?

everybody is ignorant @ something.the more we work together, the less ignorance there is floating around