Did they ever produce a slant 6 4 speed with a console in 1966?

That is not definitive, as the 4 speed trans was different between 65 and 66.
One other thing, that list does not show a 3.91 gear as an option. I did have a 65 Valiant with a 170, 904, and 3.91 SG 7 1/4 rear.