how big of fuel line do i need

I would agree with those who say get a guage first,it really is trial and error.My good friend ran a blown dual carb engine for years with a single electric pump and a 3/8 line and it didnt benefit at all from larger line/pumps ect.I stepped up my fuel system a little from stock in a 12.50 car and saw no difference,bought a guage and confirmed I didnt need it,it really depends on alot of things so its always best to check first.