NC transmission in NA/NB

Talking strictly about the 5 speed. Gear ratios are the same, center boxes look very very similar. Do you think it just takes an NA/NB bellhousing, tail-end and a little know-how? Not sure how the NC trasmission is attached though (PPF and whatnot). Maybe it's more like the gear set from the NC is just removed and placed inside the NA/NB box?

http://nielex.net/maintenance_tmsw.html

NA/NB
http://i.imgur.com/wpM2RQa.jpg

NC (bottom)
http://i.imgur.com/TNGZZ4h.jpg

I think it's a swap of the internals.

Super curious... might start checking for a 5-speed wrecked NC locally.

Thanks for this!