I'm curious if there is any difference between the US spec 6MT and the JDM version. Does the new center-diff change anything or would swapping the US spec onto a WRX be the same as with a JDM?

Reason I ask, is because if I did the swap, it would be far less expensive to do buy parts through a dealer here.

 

I seriously doubt that with the costs involved in engineering the 6spd that STI would spend even more money to make a seperate version for the US market.

 

Really my only concern is how the new center differential bolts up... because I sure wouldn't be buying that.

 

If your going to swap in a 6spd then why not swap the entire thing rather then try to swap pieces of it which won't work since the transmissions are very different. If you have a US WRX then you could swap the gauge cluster in and all of the wiring for the DCCD. People used to swap the older adjustable center diffs into the old school GC body cars. The transmissions will be the same. The only difference between the US STI and the JDM one is the motor and the seats.