1966 Ford Mustang. Original 289 4V Engine Identification Tag. For C4 Automatic Transmission and Thermactor Emissions. This is an ORIGINAL FORD TAG. Stamped [ 289 C 66 10 (FoMoCo) and 6-A E 235-S ] Removed from a 1966 Mustang GT with 289 4V Motor. IMPOSSIBLE TO FIND ORIGINAL. Please email with questions. 081122-21 WE HAVE AN EBAY STORE WITH THOUSANDS OF ORIGINAL and NOS FORD PARTS. CHECK IT OUT.