Where to start? On our race Cobra producing 500 bhp we would return 6 mpg at full racing speeds where the throttle was fully open for the majority of the time. Average speed for a lap was about 80 mph, depending on the circuit. At 80 mph and 5 mpg we would burn 16 gallons per hour. In old units that is about 128 pints (64 quarts) per hour, or about 2 pints (1 quart) per minute. Even for 5/16" fuel line that is not a lot. We used 3/8" to be on the safe side, but also ran large bore fuel pressure regulators and fuel filter bodies. I am sure the Drag Racers can burn fuel much quicker than that, but they would be producing 800+ bhp. Answering your question, the 45 psi is not the flow rate, only the pressure pushing the fuel down the line. A Holley carb only wants to see about 5 psi, so 45 is major overkill. The pump requirement is 2 pints per minute or just over 1 litre per minute. A Holley red top fuel pump delivers 97 galls per hour at 7 psi or 12 pints per minute which is more than enough! They also have 3/8 NPT inlet and outlet connections so I would suggest going for 3/8 Aeroquip hose and fittings. Sorry for all the numbers and conversions, but that is how we worked it out for ourselves. Good luck, Andy.
PS I am watching a CCTV monitor of one of our mares who is about to foal, so I doubt I'll get much sleep tonight! See even racers have a life outside of cars!