Newbie with a fuel line question

[Stirdr]

I am attempting to resurrect a '72 Blazer that has been severly abused. I am new to the gear-head life - but I am adventurous!!! The Hillbilly owner before me had a *small* engine fire and installed a new crate 350. After copious ammount of duct tape and solder - he got it to run and sold it to me. I am almost complete in getting it road worthy - rewire, repaint, sacrifice to the God of BowTies... I am tracing lines from the tank - one goes to the pump up front, one is the filler hose, one goes to the sleave around the filler hose, and two join another and go into this sealed tube that is located in the rear driver side cargo panel. From that tube I follow a metal line to the engine and then....nothing. It just hangs there - waiting to be connected to something. Any ideas????