I got install kit 3734529 but ran into issues with it being too far forward. I did some research on the forums here and ended up purchasing mounting plate 1950163 with spacer 1954319... That's where I'm at right now.
Since your at this stage have you tried the stock adapter alone? Albeit I'm using a ST-10 I shelved the Hurst adapter and spacer just for the location of the stick to the land where I liked it best.
I found the the stock adapter without the spacer kept the stick away from knee
but again, that's me though.
The first pictures have the spacer the last picture I posted has no spacer. The issue is beging able to shift. When it hits on the hump it can't be shifted only moved side to side. I may end up having to make a custom bracket as no one knows the perfect mount for this set up... Not even hurst...