Good afternoon gentlemen ,
​​​​​ I have a 71 cutlass, I知 doing an ls swap and I知 confused about the fuel system. I have a main and return line. I値l be installing another out of tank fuel line. Would I need to worry about the canister? Can i just delete it?

 

The black vapor canister up behind the passenger headlights?
That's a vent line. It should run to a rectangular box sandwiched vertically behind the rear seat, and one or three vent lines run from that box to the actual tank. The idea being that the tank can breath into that vertical box and any fuel slosh gets caught there. Fuel vapors work their way forward to the charcoal can (the black thing) where the charcoal captures the fuel vapors. Later, when the engine is running, the engine pulls just a little bit of air through the charcoal can to suck out the vapors. This lets you run a sealed tank. If you delete all this, then you need to run a vented cap, which also means fuel has a tendency to slosh out the back when you floor it.

You don't *have* to hook vacuum through the charcoal can, but since the LS had provisions for emissions, you can just use the solenoid and whatnot to do it. Just note that it needs to be metered - make sure it's restricted by putting a plug in the line with a 0.040" hole or something.

You want two supply lines coming out of the tank??