I am very glad that I decided to keep my hand-me-down '84 300D turbo after the automatic transmission failed. I am even happier that I decided to replace the automatic with a manual 4-speed.
Now that the clutch is finally broken in completely, the difference in power to the wheels is quite noticeable.
I would suggest that anyone toying with the idea of such a conversion project DO IT!
The result is simply a more fun turbo diesel - - (and no more 240D manual envy).