ok im getting rid of my old fuel lines and running new. i was looking in summit and found fuel lines like i like on is 1/2 and the other is 3/8. i asked my dad and he told me that i should go with the small one to keep the pressure up. i am switching to a bigger pump and a afpr. what size do u guys think would be better? thanks

First off why are you ditching the old fuel lines, are they Damaged ?

Secondly, The pressure will not change regardless of the Diameter of the line.

1/2" is a HUGE fuel line, you Don't need that.

im redoing the car from the bottom up. i figured that since im doing it i might as well put new lines on. second, i have the firerwall black and im doing as much as possiable in anodized red and i found fuel lines like that. 3rd im going to be buying a fuel cooler and i will need a little bit longer lines.