I am happily blue printing and upgrading my XK engine, to fix all gaskets, valves, cylinders, and main bearing seal. As long as the engine is out - does it make sense to re-build a transmission and overdrive?
Im concerned that - given the older state of the engine rebuild (1980s) - the transmission, though working fine now, might benefit from a re-build. Of course Im not eager to spend money on something unnecessary. Thoughts?

Is it possible to open transmission and overdrive and determine condition, without major hassle - or is it not wise, or easy, to open a transmission without committing to a rebuild?

thank you all!

Jeff