What i mean is that the box is probably a physically different size to the T5 bellhousing the cossie one mates up to, so its not going to bolt together, likewise the spline probably wont fit the clutch.

Going to be a lot of hassle to do it just to end up with an engine thats not any better than a 20VT engine that would bolt straight up

Personally, i wouldnt bother TBH