Hey guys, getting ready to run the fuel lines with my engine swap, but I need to know which lines go to what on the fuel sending unit. The one I have was "hacked" out of the car, and I have to double flare the ends and use couplers, but other than that, the unit is fine. I know that the 3/8" line going to the pump is the pressure side, and the other line that runs down next to the pump is the return, which leaves two lines, one for the charcoal canister, and one for that little vent that I remember seeing under my '87 Iroc with the many times I replaced the pump. How can I tell which is for that vent and which is for the canister? Any help is greatly appreciated!

 

From the fuel tank sending unit assembly:

The pressure line is 3/8 with a metric o-ring fitting
The return line is bulbed 5/16 inch bulbed
The charcoal vapor line is 1/4 inch bulbed
The vent/valve line is 3/8 bulbed

 

cool, thanks!