Fuel Lines From The Tank-Which One Is The Fuel Supply Line?

[1996*GMC*SHORTBED]

1996 GMC 1/2 Ton Shortbed. Of the two steel fuel lines coming from the fuel tank(one smaller, one larger), which one is the fuel supply, and which one is the return? Thanks everyone. (P.S.- I know that the third line goes to the charcoal cannister).

 

[jessezipper]

the little one is the supply large one is return