maz duh
+1y
The 3 lines are feed, return and a fuel vapor line that hooks up to your charcoal canister. The charcoal canister allows the fuel vapors that will occur on a hot day to stay in the system and not vent into the atmosphere. In many areas you will need to keep it to be legal. most plastic cells will have a feed and return fitting on them already, you can pick up an extra fitting and drill the cell out for it if you want to keep the charcoal cannister. Circle track shops are usually a good place to pick up a fitting if you need it. Remember that eletric pumps are better at pushing fuel than pulling it as well so if you are planning to move your cell behind your axle it might be a good idea to move your pump closer to it as well. Post back if you need any more info. Good luck.