fuel pressure at 8psi

did your black pump come with a regulator? "...Fuel pressure regulator is required (recommend Holley P/N 12-704 for gasoline..."
Thats the screw I was speaking of. Does the QFT use a carb jet to regulate the pressure by restricting the return side? Maybe try a larger jet or remove it completely for testing. you could probably just drill it out if you dont have jets handy IF it uses a screw in jet. ALSO "...It is advisable to use the same size return line as the feed line from the fuel pump to be certain the return line can handle the same fuel volume as the pump output. If the return line is too small it will not be possible to reduce the fuel pressure to the desired level..."