a833 with 904 yoke??

There are some '66 transmissions. They are not all that common, and my own '66 273, 4-speed 4-barrel, Dart didn't come with one. They must have burned their inventory of them up in /6 cars in '67, because according to my parts manual, it doesn't exist in '68. I've reubilt a hundred A833s, and I've never run across one yet. I think Mopar did alot of evolution within car lines right there on the assembly line, so strange things end up in alot of cars.
I've got a '75 NON-OD 4-speed with a cast case, and a 309 gearset out of a Duster... another bizarre transmission, but not the norm.