After seeing a kickdown linkage for a Super Six sell for over $200 on eBay, I thought I would post this little trick I learned to save everyone some time and money. This will only work on post 66 cars that don't have the twisty rod style linkage.
As you can see, this setup consists of the Super Six intake and carb, but retains the complete original one barrel kickdown assembly. This is installed on a van, but the kickdown is the same for cars.
The piece of aluminium was bought at Lowe's for around $10. All I had to was drill two holes in the metal 7.5 inches apart (this was the distance between the carb throttle stud and the kickdown bracket on the one barrel kickdown with the transission lever all the way forward). You can see that I drilled a little but extra out up by the carvb. I did this for adjustment purposes but then realized that the adjustment at the transmision should be all I need.
This setup maintains the proper one to one ratio between the movement of the throttle and the movement of the kicdown. I have driven my brother's van with this kickdown installed and it works great! Cars will have to deal with the throttle cable attachment though.
You could, of course, do a much cleaner and more professional looking job than a big rectangular chunk of aluminium, but hey, it works.