Fuel Line Mod?

I believe you are talking about the Holley carbs that have one side of the bowls plugged off. If you remove the plugs and install a fuel block and aim it toward the rear of the vechicle. One side of the carb bowls is used for the fuel coming in .. the other side is returning to the tank. By using a electric fuel pump you leave it on after you shut the car off for awhile and it will recycle cold gas through the lines, carb, tank over and over.

Is this what may perhaps you are talking about?