I bought a 1964 Comet that had a correctly date coded 289 Hipo and a 4-speed transmission out of Michigan about 9 years ago. Supposedly 289 Hipo Comets are a myth. I can tell you that the VIN number had a “K” in it although that is also not a telltale sign of a factory Hipo Comet. This Comet had a single exhaust with standard 289 cast iron manifolds. I have lots of photos from this Comet on a computer that is in storage. It originally came out of Las Angeles, went to Salt Lake City and then to Michigan. Needless to say the rust was so bad the car was not restorable. Everything on the car was date coded perfectly for a factory built car, it was white with a blue interior. I still have access to the engine which was complete from the
oil pan to the carburetor and from the water pump to the bell housing, the bell housing was the standard aluminum production part not any kind of scatter shield. I still have the transmission (T10) and the bellhousing.