Fuel line and mystery line.

[gntblue]

Frame off restoration of a 74 k10.  I have all of the brake lines routed and i need to order the fuel lines.  The truck had a two output sending unit coming out of the tank.  Now obviouly i know which line was the fuel line since it was hooked to the fuel pump.  But. There is a second line that ran up with the fuel line and then turned and followed the front cross member acorss the truck.  I cant remember what that line was for.  Is this a return line or a vapor line?  What does it connect to?

I will upload an image tomorrow when i get to work.


Thanks

[bd]

5/16" vapor line to the carbon canister.

[gntblue]

Thanks thats what i thought