I think his stage 1 starts at like 3200 or 3500, his stage 2 requires new internals on top of the upgrade (I think its an upgrade from a T3 to a t3/t4 hybrid, and stage 3 you'll have to pm him about, but it will probably require his straight cast tranny too (OMG strong!!!)...his stage 1 will probably see you at around 220 hp, like the stafford kit, his stage 2 is around like 280 I think, and his stage 3 I haven't heard any numbers from yet, but I think its just over 300 hp, and over 250 ft-lbs of torque
...hence needing the new tranny...also, with his new tranny he's not only having the gears re-cast, and straight cut out of chromoly steel (like a rally car), but he's leaving fifth and sixth gears open, which will increase top speed. He has the 6 speed euro tranny, which has the same housing as the Us spec GTS tranny, just with different gearing and internals, so if you want a stage 3 Turbo on your GT, you are gonna have to ave your engine rebuilt with the MWR kit - lower compression and stronger internals, plus sleeves and possibly an o-ringed block, which will run you around 3,000 in parts, plus around 4,500 or so I would imagine for the Turbo kit, and another $3,000 for the tranny...which comes out to just over $10,000 in parts alone, plus labor. Given its a ton of cash, but its also a hell of a lot stronger, and you'd have a seriously fast car, with no reliability issues at all because its been built to take it.