A855 - 5 Speed

Not necessarily.
As I stated earlier, in my case, original bb car, didn't want to cut it up, or deal with any potential issues or unknowns.

More importantly, iirc, aftermarket trans would interfere with the bench seat.

Also, I could only find stories of people who knew a guy who had one, but little direct experience, which is why I started this thread in the first place.