Lose either the mechanical, or electric pump. You don't need both. I have run the holley blue pump on low 11 second cars. Also have run high volume mechanical pump on 11 second cars. You don't need both. Easily check output by unhooking fuel line and pump into a can for 30 seconds, or 1 minute, and see how much you get. Where is your gauge picking up its pressure reading? What makes you think you are running out of fuel? A 12 .6 second small block can easily run a 3/8 line with either pump, and not run out of fuel. I would tend to agree with CP about the filter, however I ran a GF 481 ac delco filter, between the tank on pump, on my last car. Ran 11.6 with it.
Just had another thought. The Holley blue pumps that I ran many years ago had a screen on the inlet, maybe yours has some "crap" on it. Take the bottom off the pump to access it, and throw it away.
