6paks came from the factory with a 8-9lb pump, BUT they had a .060" return orifice in the vapor separator that helped control fuel pressure. i just went thru a high pressure fuel thing with one of my street cars. anything over 7lbs can cause problems and seems that 6-6.5lbs is a sweet spot. i use the 6903 pumps and do some mods to them but run a return of some sort. i also think large needle and seats can be a problem with higher pressures. the floats just can't control the flow, especially at WOT. i don't know your power level but stock 6pak fuel lines with the separator can handle 450hp. if you want to keep the braided hose then try to rig up a return line. i prefer hard lines myself, but braided may be better for someone pulling a lot of maintenance.