"The Easy Performance fuel pump rewire kit was designed to replace the anemic stock 18 gauge wiring. Most GTPs are losing between 1.5 and 2 volts to the stock pump because of line losses in the wiring. Since our fuel pumps are positive displacement rollervane pumps, this matters A LOT! Flow is directly proportional to fuel pump speed which is directly proportional to applied fuel pump voltage. Upgrading your fuel pump wiring will give you quite a bit more headroom with your stock pump.
This kit upgrades your power and ground, look for 1-1.5 volt increase at the pump. Uses factory connector so there is no need to cut wires at the pump. It will not affect pump life and does not increase alternator load. Once installed it's totally hidden. No worries about taking your car to the dealer for warranty work.
Real world testing shows increases of 2-3 psi max fuel pressure. Stock injectors usually fall off in the 310-320WHP range, 42#'s around 340-360. This kit increases those numbers by about 10%. This of course depends on the year of your car and many other factors but that gives you an idea of what to expect.
Further gains of about .4 volts can be had with a alternator rewire kit."