Torsen for Hyper ST?

[Jabe]

I would like to apply my Hyper ST with torsen central diff, but theres a problem.
I have flipped my motormount, so motor is in front and thats why my gearing is restricted to 52t spur.
And so far i have found only 48t spur for Hobao/Ofna torsen... Is there any torsen that would fit Hyper ST and would have spur close to 52t?
I currently have 52/12, but havent made test drive yet, so i dont know how it works.