Ok ,,, Looks like the part # F1ZZ-6049- B does exist as found in the
Obsolete - Supercede - Interchange Manual FPS 7632-5 January 1994
http://www.fordpartswiki.com/getpage?pageid=158340
http://www.fordpartswiki.com/getpage?pageid=158516
appears to be the superseded part # for a 87 and a 90 truck head, E7, and F0, and given a Mustang designation as F1ZZ-B .
Curious to know what it looks like, NHRA tech sheets has the casting # as F1ZE- B , however, I don't see any published runner volumes , valve sizes, chambers, etc...