Fuel line connection 6an thread to 5 /16

In the carb installation book they say
Use 8134 chrome fuel line. (I did)
It says it has a 6 an thread on it.
I contacted edlebrock and they say they have a 6 an to 3/8 adapter but they don't have a 5/16 connection.
Click on my links. There’s both male and female adapters to go to 5/16.