You need a 7 quart pan to keep from running out of oil in the pan under WOT with a high pressure pump. You just don't have the filter in place correctly if it is leaking. Get a new Motorcraft or Wix filter, then go backwards to spin it on to get the threads lined up, then spin it on forwards, only using your hands to get it tight. If it leaks after that then you have other problems than the high pressure pump.