You only have info on the RWD variant.... Absolutely nothing about the FWD variant...
The 6T70.
http://en.wikipedia.org/wiki/GM_6T70_transmission
Seems to be high feature only... Which means GM High Feature. Not metric.
Bellhousing is integral which means adapter will be more difficult.
I'm not so excited. Thats stock L67/L32 torque levels right there. Touch the motor at all and you're past its rating.General Motors rates their 6T70 to 315 hp (235 kW) and 280 lb·ft (380 N·m) and the 6T75 to 315 hp (235 kW) and 300 lb·ft (407 N·m).
So clearly you haven't done any research on the topic.