Sorry but to fit cams into a 350Z motor is a lot of money , easier to do with the motor out in our opinion;
Then if your running wild cams you need to run more compression as the static compression will be dropped as the cam is wilder; new pistons needed;
I know Sasha when he was running his own company used to tune on a Dynapack. Used to throw idea between us. They used to use SAE conversion which will add around 10/15bhp to a bhp figure;
Your end up with a motor with a engine with a 2000rpm power band max that will not be nice to drive at small throttle openings and low RPM's , will require rev to make it go properly;
That's why us UK tuners always say go FI makes a more fun car easier to drive quickly on the road , but if the car is going to be a track car/race car yeah go for NA power but your also need a sequential gearbox to make the most of the narrow power band.
I did manage to run a car on our in house dyno today and recorded Vac in the plenum , reading in Absolute KPA we saw a increase in Vac from 0 to approx 0.003 kpa at the rev limit such a small increase , my thought is it the TB or the plenum design;
Same car recorded 270hub bhp thou pretty good number for a DE motor , circ approx 310 flywheel bhp , stock motor , headers, ART decat pipes, plenum spacer,stock airbox with velocity stack, Milltek system and a very good reamp with UPREV. a Stock DE will give around 235/240 hub bhp we have seen from all the cars we have run over the years.
With 94 K miles on the car as well