No, I'm referring to the VC unit out of the Outback rear diff that I'll be cannibalizing for its 4.444 ring and pinion going into my SVX rear.

I'm wondering whether the VC unit can be bolted to the front ring gear in place of the existing spider gears.

I'm doubting that it would work properly... IIRC the STi front differential is a 1-way unit, i.e. it only limits slip on acceleration. A VC unit would tend to work whenever there was a difference in rotation between the sides, so it would probably cause erratic operation and then burn up fairly quickly.

I'm just brainstorming through my fingers, ya know....