What size are your fuel lines? You need volume as well as pressure.Also what size is your fuel pressure line going to the gauge? A few years back I had the same problem and like you had plenty of pressure 7lbs all the way down the track with a 1/8" plastic line to the fuel pressure gauge,changed it to a 3/8" line and had only about a 1 1/2 of pressure go through the lights. You also might want to check the size of your needle and seats,the standard size don't cut it for a Big block Mopar.