Purpose of this thread is to document the approximate change over period during 1966 Metuchen production.
The subject was originally explored in a 65 thread about the subject.
https://www.concoursmustang.com/forum/index.php?topic=25544.0As usual will invite input with car VIN and style of wheel house while I survey the collection of pictures and such I have. Will as usual post in this post our findings and conclusion, if possible, as they are determined.
Thanks
Early style without spare tire depression

Later style with spare tire depression

Initial scan of the pictures I have suggest sometime in the 6T21xxxx's or so right this moment.