Fuel line? Is it enough

Not that it matters but your 68 Formula S came stock with 5/16", just like they all did.
still got it laying out beside the garage if u want to come and take a look at it. ben a plumber for 42 plus yrs., I`m sure I know more about pipe and tubing sizes than you, unless your one too. It possibly could have ben replaced by the previous owner or owners,but it was as factory as it could get!???????????///// bob