[unruhjonny]

I need to make a small correction;
the Muncie three speed was a Chevy only deal for the 1969 model year;
Keep in mind this was at a time when divisions got to have exclusive use of new products that were developed by (or through?) them.

The Muncie three speed was the base transmission in all 1969-SS models (afaik).

For 1970 the Chevrolet division exclusivity was gone, and in a move I don’t quite understand, the Muncie three speed was nla behind any Super Sport model;
It was used in some non-SS vehicles that required a HD three speed.
The trucks continued to use the Muncie three speed through to 1974.

As already mentioned the 1970 GM A-bodies all now used the Muncie three speed - except for the Chevelle Super Sport;
This continued through to 1973 or 1974 - I am a little unclear when the transmission stopped being offered for use in the A-bodies.

The Firebird had the Muncie three speed fir 1970 & 1971, and it has been suggested that it was dropped for 1972 because of how few were ordered.

As far as I know, the 70/71 Camaro never used the Muncie three speed.