It didn't come with a barb for a return line thats why you didn't get one. That stainless line will screw right into the end of the fuel rail, its a 4an connection. That barb is a vaccume restrictor, it goes inline with the vaccum hose to the top of the sfmu. That bleed valve is connected to the sfmu, some people use it, some peole dont. That little barb with the screw in it came with the bleed valve. If you don't want to use the bleed valve then unscrew that flat head screw from the brass fitting and take the bleeder out of the sfmu and put the screw where the bleeder is at. There were also some instructions in there that came with the sfmu, the dark spring is in it and the largest disk is in it. You might want to check how snug the allen bolts are in there though because I didnt have an in-lbs torque wrench on me when I tightend them down.