METCO Ford Fuel Line Adapter (Feed) This adapter is a part of our popular MFF0008 fitting assembly that adapts the factory fuel feed line found on the 2005 & newer Mustang GT to our billet fuel rails. The fitting is CNC-machined from stainless steel with 3/8" female threads at one end and the necessary coupling at the opposite end to mate with the OEM fuel feed line. While specifically designed for the 4.6L V8 in the S197 Mustang, it may also fit other Ford EFI applications.