We spent a lot of time finding a good plug. Its a very skinny plug. We actually found the GT-R plugs to work well in the 370z. The gap out of the box on those was .030". That's a DILKAR8A8 plug. You used to be able to only get them at the dealership but my main NGK supplier should be able to get them for me now so you shouldn't have too much issue tracking them down.
Thanks,
Alex Goodwin
AlexG@motionlabtuning.com