having a fuel issue on a northen sportmod with a 602 crate

have a sportmod 602 crate,650 holley carb, holley new racing fuel pump,and a aeromotive x1 bypass regulator. the prolbem is and maybe its normal but the fuel pressure starts out at 7.5 then it drops down to 5.5-6 running down the straights. i have the fuel light set at 6 and it will be on all the way down the straight. the car seems to run ok, does not run hot or miss. dont know if i should worry about this or what i can check to get more pressure. thanks for any ideas

I would set your f/p higher. I think I run 8-9psi at idle.