My fuelpump broke down yesterday when I was out wheeling. A friend gave me a ride home so I could take the fuelpump from the blazer to replace the broken one on the sub. When I got back to the sub I discovered that that fuelpump had two fuellines from the tank but the "new" one from the blazer has only one. I mounted it anyway just to see if it was going to work, since i had to get the truck home it was late, dark and raining and the sub ran just fine with just one fuelline connected. So the question is, what is the return fuel line for on a carburated truck? Seems like it's working fine without it.