I was reading a article yesterday regarding SEMA that Nissan is already using Nismo suspension parts from the 370z on the "400", namely FUCA's, tie rods, end links, rear camber links, mid links, and traction arms.
Nismo will have a 6/4 piston brake kit with larger slotted rotors and optional $450 pads out early next year which would be interesting if it fits the 370. Road & Track tested the pads in the base brakes on the track and raved about them.
Also for the 400 will be a coil over kit with rebound adjustment, adjustable anti roll bars, LM-RS1 wheels intake, larger intercooler, stainless exhaust system, clutch and flywheel designed to hold 800 hp, carbon mirror caps, carbon steering wheel trim, AL fuel filler and oil filler caps and titanium shift knob.
Moving forward it will be interesting to see what aftermarket 400 parts will also fit on the 370 as well as 3rd parties doing their research and simply adding the 400Z to their fitment listings of parts previously made for the 370.