Have a look in the Dyno results thread nowhereboy. http://www.350z-uk.com/topic/23450-dyno-results-info-thread/
After my UpRev I got 293.4bhp from my 2003 DE which I'm pleased with. I have a H.Dev plenum spacer, Invidia Gemini exhaust system, Berks HFC's and a Stillen air induction kit.
On the same day at Horsham Developments a similar modded Zed (2004 model DE) got around 280+bhp from his so it will vary from car to car. Also ambient temps/fuel/engine internal condition & the dyno used will all contribute to different figures.