From the wikipedia on the
Essix V6:
A nine-digit serial number appears on a label on the right side (front) valve cover. It also appears on a barcode label on the transmission side of the right side head.
Applications:
1982 Ford Granada
1982–1983 Ford F-series
1982–1997 Ford Thunderbird
1982–1997 Mercury Cougar
1982–1986, 1994–2004 Ford Mustang
1982–1986 Mercury Capri
1983–1986 Ford LTD and Mercury Marquis
1988–1995 Ford Taurus and Mercury Sable
1988–1994 Lincoln Continental
1995–2003 Ford Windstar