release bearing differences, fitment

[RoadRace]

in the race car, i have had real issues with shifting - I have the BW T5 from the 83 280ZX Turbo. it shifts like a bag - hard, lots of effort, sometimes grinding - sounds like syncros, right?. so i took the trans apart and found the syncros to be Ok. so i talked with a tranny guy i trust and he said the T5 shifts real crappy even when its working good (i can agree with that), but he thinks the clutch isn't fully disengaging, causing the trans to hang up while shifting. As i thought about that, i thought no way - new clutch, and hyd cylinders. he felt the flywheel was machined too far down, putting the clutch assy just far enough away to make it hang up. i think thats stretching it just a bit (if you'll forgive the pun) and i then remembered that the release bearings are different for different Datsuns.

 

So - how are the release bearings different? are they longer and shorter or wider and thicker - who knows the physical differences?

 

also, does the release bearing go with the tranny or the clutch or the engine? how is it identified as a part of what assembly? is there a part number??

 

thanks