Just bypass the Hobbs Switch, "pressure transducer", by splicing the two wire together so it runs all the time.
I made over 700 RWHP with the stock rails on E85. I did upgrade my feed line to -8 though.
As long as the pump can keep up with your power level, the line shouldn't matter a whole lot.
Sleeper, how was your fuel system set up when you were running the 700hp?