it was listed for sale in the classifieds. Not sure about fitment in stock location. I'm running the older gt3071s and there's not a lot of room in the stock location. I'm pretty sure the GTX housings are slightly bigger. Garrett has some good shop drawings of their turbos on their website for comparison. Maybe someone here can confirm fitment of the GTX3071/76 in stock location?
I've been curious about this upgrade for my Z, but if I ever decide to go this route I'd most likely go with a custom manifold/downpipe setup with a reverse rotation turbo on the driver side. Or just go with the BW EFR's instead of the Garretts.