Huge undertaking. To my knowledge, in the later car, the ECU monitors the transmission, ABS, the airbags, the climate control, gauge cluster, airbags, power steering, and a myriad of other functions.
You'll basically need to make sure you get all the sensors and systems off the G37 and integrate them into the G35. Just having the engine out of the G37 doesn't help. You'll need the ECU, the TCU, the ABS controller, the full harness, the cluster, the audio/HVAC center stack, and everything else the harness attaches to. If *ONE* sensor doesn't see the values it expects, AND if it sees two values that don't jive, it's limp mode time.
That doesn't even include all the custom fabrication to the mounts and brackets and accessories to make them all fit. VVT differences are the least of your worries.
If it were mine, I'd find a good low-mileage VH35HR, toss a supercharger on it, and go to town. WAY cheaper, no drama, and more power.
I've been down the road of misery (MR20 into a 2009 Cube) and it was a colossal failure - even with a Nissan GTR Master Tech, a retired Infiniti Master Tech, and three fabricators involved.