Why replace your factory fuel feed line? Restrictions in the factory line cause pressure drop from the fuel pump to the rail; depending on the application a fuel pressure reading at the fuel rail might be 5, 10, or even 15psi lower than the fuel pressure at the pump. Take a gander at any fuel pump flow chart and you will find that fuel pumps flow significantly less at higher fuel pressures. To put this into perspective a Walbro 400lph fuel pump flows roughly 253lph at 90psi (13.5 volts) in comparison to 300lph when pressure is reduced to 75psi. An additional 50lph translates into almost 100whp of additional fuel capacity on E85!