Has anyone ever used this wiring harness for their stock fuel pump?

http://www.jegs.com/webapp/wcs/store...1175&langId=-1

I am thinking actually about getting the racetronix fuel system...but i was looking at other alternatives first. Any ideas? The above harness is said to increase the voltage to the pump by upto 20%. what would that translate to in terms of fuel flow and HP support? I am expecting aronud 415rwhp with my new setup and want to make sure i feed as opposed to starving the beast...

Any input would be great!

Thanks