Question I couldn't seem to find an answer to when I searched: Are later D series trans (02+) internals swappable with earlier D series (d16z6)? I have a D16z6 trans that needs some internal parts, and found a later gen 03 civic EX trans locally. Specifically I'd like the shifter forks, and the 4.5 final drive.

 

As for the transmission itself no - The bellhousing pattern is different and if I remember right they started using cable shifters on the 7th gen Civics rather than the hard linkage of the older days.

The internals themselves such as the forks or FD and other gears, I'm not sure on but I'd wager them to be incompatible. D17 engines and 7th gen in general was an oddball time period.