5.3 fuel line question

Have a 2005 5.3 and plan to use the truck manifold and adapt to the stock fuel line (in 62 Nova). My question is what is the other line for (in the picture at the back of the manifold), don't know if the lines may have been bent and should be in a different position. A picture of how the lines run on the truck would be very helpful. Thanks

That's the EVAP/vapor line. There is a black plastic tube one the intake manifold that runs to it. I can see it in your pics. Looks like the end was broken off.

You're exactly right, now that I know it's just a vaccum tap i'm going to cap it off for my car...
Thanks

Be sure to vent the tank if cap it