67 plymouth barracuda fastback 273/727

In 67, most all of the /6 & small block cars, came with the 904. I personally have seen a 727 in one that came from the factory, with a 8-1/4" sure grip rear end. They could order it anyway they wanted back then. This car also had come with the H.D. suspension package. I guess it could have been ordered for trailer towing purposes?