[68c10airstream]

The shimming was just an example. Looking at your trans the end tapered roller bearings would be suspect and any selective shims to adjust end play if this is the case on this trans. Sloppiness anywhere, shift fork pads, slider hub, the areas you highlighted, etc it all adds up. In my younger days as a subaru mechanic, i fixed many manual trans's with exactly your complaints and needed all the parts you mentioned and more because of mainshaft walking. Fixed a few t-10 4 speeds with shims because of mainshaft causing 4th gear pop out iirc. Did you narrow up the front end track width? if so what rack did you use?