The stock pump should be fine... Usually the cause of low fuel pressure is the sock in the fuel tank is clogged up with crap... I always clean the tank out, replace the rubber lines, and add new fuel filters and rebuild the carb. That is the only way to be sure to have a good fuel system... Might as well get a new fuel pump while you are at it since the rubber inside goes bad over time and gas leak fuel into your oil.
