I am trying this very swap right now. So most of the day I was getting a slap stick to work in my 1974 360 duster factory console car. Here are my findings.
E-body z-bar to short to work from a Cuda.
But measured the distance on holes so I could use those findings on
a 1968-9 a-body z-bar because the top bar is above the factory top bracket.
My 74 factory top bar is below this and has a curve so you can't drill a hole closer to the rod to give you the proper ratio for it to work. The older ones are flat bar no curve or up kick.
Here are the measurements
The top bar now measures 2.250" centre of rod to centre of linkage hole, on
top z-bar flat bar.
The
bottom bar measures 3.65 centre of rod to centre of linkage hole stock no adjustment needed.
I used a slap stick from a 1978 charger/road runner.
Because a a-body shifter measures 2.00" throw Vs slapstick 1.60" throw you must shorten the swing of top bar.
from 2.500" on the factory a-body z-bar to the
2.225" like on a cuda
Also the Cuda slapstick shifter shaft/ball was to short to fit the a-body console. T-handle was a no go as well.
But did you know that a 1978 charger/road runner has slap stick shifters as well on some models and is taller shaft/ball which fits nice.
Your shift indicator will show park nice but 1st gear looks closer to 2nd as throw is less than the factory one but I'm good with that having the slapstick.
I have not test drove car yet but it shifts nice and you hear the detent working in all spots. A small adjustment on the linkage was needed to make park and 1st line up at each end of the throw. I have solved my quest. Being that the shifter shaft is straight not curved like the factory one, it comes close to the console in park may even tap it.