|1964 1/2 - 65 Mustang Quarter Panel Extension End Cap without groove for rubber seal.
|Quarter Panel Extensions shown installed on Mustang.
There were tons of production changes on the '64 1/2-66 model (and later) Mustangs. One of them involved the quarter panel extension end caps. Starting sometime in late '65 production, these quarter extensions were made with a groove in them to accommodate a rubber seal. The earlier cars simply did not have this groove and did not use the rubber piece.
We can only assume that this change was made perhaps due to some time of problem with this piece fitting right against the quarter panel. San Jose produced Mustangs that I have seen have these "early" quarter extensions right through June of '65 production. I don't think it is usual to even find one early and one late originally installed on the same Mustang in this production time period.
Keep in mind that even though the later cars use the seal, the seal is not seen once the quarter extension is installed on the Mustang.
|Late '65 Mustang Quarter Panel Extension with groove for rubber seal.
|Rubber Seal shown being installed on Mustang Quarter Panel Extension.