I looked at a picture at rock auto and it cost $57.00 it appears to be the same as a pressure regulator. Pull the vacuum hose off the end and if leaking replace.
http://www.autopart.com/tools/toolsmain/tool/T_3440.htm This is the type of tool needed.
Your looking for pressure above recommended fuel pressure.
You can also call Ford parts and ask them they should tell you for sure.