It's up to you. If you want to point at the fuel line and tell people it's 3/8", go ahead and upsize it. For the purpose you said you plan to use the car, a stock fuel system with mechanical pump should be fine. You'll need the larger fuel capacity at higher RPM. Where I live, if you spend much time at 5000+ RPM at cruise ins, you'll be asked to not come back. And on the street, you'll be asking for tickets.