Dear ladies and gentlemen,

After searching for hours I am still confused. Though I learned a lot, it looks like it was not enough...
I own a 1991 CR-X EE-8, OEM fitted with a B16A1 and a Y2 transmission, which has torn the teeth off of the countershaft.

As far as I can find, these Y2 trannies are internally the same as the Y1 trannies except for the final drive, the latter being shorter.
I also read here that the countershafts of a Hydro and Cable aren't interchangeable, but stumbled on a post somewhere here stating that it can be done with some modification...,
but no link to the post and could not find a thread containing information. Maybe I am not looking with the correct search words? No native English tongue...
After some more digging I found a site selling MFactory short ratio gears, stating they fit: Y1/Y21/S1/S4C/S80/S9B transmissions.
Example of an order number: MF-TRS-01B5A-4-141
This being for 4th gear, ratio 1.410.
Yet a final drive set is stated as is for: Y1/S1/J1/Y2 transmissions
Order number: MF-TRS-02B49C
If read correctly, the Y21 transmission has "hydro" internals, yet being cable operated. The S80 being a Hydro tranny for sure, it only makes the offered short ratio set more confusing to me
Does such a gear set only contain 1 gear, only for the primary shaft? If not, the splines of the Hydro and Cable countershafts are both the same.
Measured the inner diameter of the planetary wheel connecting to the differential, being 109mm. The bearings on it are also 80mm. 10 bolts are also checked and counted for.
Everything looks like it will fit and yet I can only get a far too short final drive of 4.9ish by MFactory. All other set are for Hydro trannies.

I would happily bolt a hydro tranny on the engine, but I just rebuild my Exedy twin plated clutch a year ago, with hard to obtain clutch discs as the only disk that fits is from a 90ish Acura GSR I believe it was
and installed Synchrotech carbon synchro's 5 months back.
Granted, clutch disks for a hydro tranny are easier to find and therefor cheaper, but all things add up to a total which unfortunately are not in the books for a while.
As of now, I am looking for a Y2 tranny, just to gut its countershaft and planetary wheel and throw the rest with the other gutted Y2 tranny, also for its final drive. Those turbo's...

My question to you fine people is;
What is the difference between a Hydro countershaft and a Cable countershaft for a 'B' series engine? Are they able to be interchanged after machining?

Thank you very much in advance!