I highly recommend Precision Z Service in Canoga Park,CA they work on all Nissan and Infiniti models and specialize in the 350Z,370Z,G35,G37,GTR models. I had them replace my clutch,flywheel,and pilot bushing on my last Z after damage occurred to my clutch/flywheel at the SCCA Autocross event. I can vouch for Precision Z Service they do excellent work and really pay attention to detail and they even found that my master cylinder cracked as well. I also had them replace my master cylinder and had them flush my clutch fluid. Go check them out they will take care of you.
Precision Z Service - Nissan And Infiniti Repair, Infiniti and Nissan Auto Repair, Car Repair Shops