4 speed/ 3 spd OD

I posted a while back about a tranny that I bought at a wrecker, Some guys on here dated coded it for Oct 1970, that was probably installed in 1971 model year car. The guys at the autowrecker yanked it from a 1975 Duster so they thought it was a 3 spd OD, but someone over the years must have swapped it.

So I was reading about 833 history on the Passion Performance website and they say that the 833 OD was acutally manufactured from the early 1970's to 1986. This had me thinking, because I thought that I read that the OD started lift in 1975.

I checked the Brewers website and they say that the 833 OD started life in 1975 just like I thought.

Whos right, I want to know if my tranny is indeed a 4 speed or a 3 spd OD, since it was date coded for Oct 1970 I was thinking it must be a 4 speed for sure. But now the stuff on the Passion Performance website has me thinking that I might have to dig deeper???

Can anyone shed some light on this???