Need advice on installing new fuel line

Are you sure this is your problem?I ran 70 passes last summer with my 410 sb in my 66 Dart with 5/16 fuel line,never cut out once.What type of ignition box are you running?

It doesn,t hurt to change it out to 3/8 line and sender,but you might have other electrical problems.Also,has your dizzy been re-curved?