Fuel Line Question

I'm installing a 408 stroker in my car and I currently have a 5/16 fuel line that is like new (installed last year). Can I leave it in and run 3/8 line from fuel pump to the carb? Or do I need to replace the whole fuel line to a 3/8, which requires new sending unit as well.? What kind of issues will I see to know that I need a bigger fuel line, or will it make any difference. The car is a driver no racing. Thanks