Last I checked Nissan didn't make a twin turbo 350Z. We're talking stock to stock. If you want to talk aftermarket, that's a different story. Let's see, just to run with a SRT6, a 350 would need a SC or Turbo. To beat one, you need 2 turbos. If you want to put a power adder on a 350 the right way, you'd need to switch to forged internals, lower compression pistons, a different fuel management system, and etc. By then you'd have spent enough money for two SRT6s! So, SRT6 wins that one in my book. Isn't bench racing fun?