I should start off with a disclaimer about my abilities as a mechanic, I'm not one. I was sent out seven months ago to buy a good family vehicle due to the coming new arrival. I wont tell you my wife’s reaction when I came home with a beat up K5 and a big smile. Before that day I had never even changed my own oil but since then have learned and done a lot. In my quest to find and fix everything on my Blazer I noticed the fuel pressure was at 12.5-13 psi. I have a Holley 670 cfm TBI that, according to the spec sheet Holley sent me, needs 15 psi. My question is will 2-2.5 psi more make a difference and if so, how do I gain this. I should note that I have a new filter and GM ($$$) fuel pump.