Originally Posted by wulfgang

Well, to answer the original question, no, I doubt the tiptronic will be up to the task. The 6-speed gearbox from the Boxster S was only rated for ~270 ft-lbs from Getrag, and from what I've read, they had weak input bearings. So I have no conclusive evidence for the tip, but I'd surmise that it's nowhere near up to the task of taking that kind of torque.

Possible alternates are the Cayman S gearbox, a G50, or anything from a 996/997 (with flipped ring gear), all of which are much beefier.