You are a wonderfully spokesman for the DSCCNA. Diesel sports car club of north America
umm maybe we can come up with a better acronym...
The miata Jack McCornack had at the Mother earth news fair 2 years ago has a Samurai transmission behind a Geo 3 cylinder. The transmission was very small compared to a miata trans. Our friend the internet says they had a 21% od in older models and a 15 ish% of in the later model transmissions. Enough to shine an led on if someone was thinking about building a drive train from scratch.
Cheers