Just to supplement the 4-speed thread....
I owned a 1963 B-body convertible that was factory equipped with a 4-speed transmission.
Galen Govier documented it as one of 17 built that year with a GM (General Motors) supplied transmission.
Sadly, to me anyway, , the factory engine was a poly-head 318 2 barrel.
I recall some heated discussion in the past to the published availability of a 4-speed available in the 300 J
and to my knowledge it has never been completely disputed. (The rumor persists that there is one out there) The trans would have had to be an outsourced
unit, not a New Process 833.
Finally, I believe there were 4-speed equipped Hemi B-body SuperStocks with the NewProcess 833s
My .02 cents