It is my understanding that it was on the Challenger R/T, T/A and Rallye optioned cars EXCEPT the very early 70 R/T's didn't get them automatically.
The Cuda & AAR got them but I am not sure if they were on the very early 70 Cuda's.
There was probably other options that I don't know off the bat but somebody will come along and correct me if I am wrong..
I believe there was a 340 Barracuda that technically wasn't a Cuda but trimmed out the same as a Cuda. Correct me if I am wrong.
As for cost they were pretty common. The last time I bought one it was less than $100 for the whole setup but that was over 10 years ago.
In 1972, 1973 and 1974 the Barracuda and Challengers were eligible to be equipped with a, handing and apreance package, it was the Cuda and Ralley Challenger.
You had a choice in engine Cuda and Ralley Challenger. Either could have been ordered as 318 or 340.
In 1974 318 and 360
They had the frint and rear sway bars, as part of the package
