Kickdown Linkage

The way it was explained to me, the trans needs a signal from the throttle pressure linkage (kickdown) in order to build line pressure to balance out the signal from the governor. This determines where the shift points are.

You want to make sure at WOT the kickdown lever on the trans is all the way back and at idle, it is not all the way forward, but just back enough to start pushing on the spring in the trans (you should be able to 'feel' where that point is with everything disconnected). If both of these parameters are met, the kickdown will function properly. If not, you can redrill a hole on the trans lever closer or further from the pivot in order to match the 'sweep' of the lever at the carb. Hope this makes sense.

Do you happen to have a picture of the connection at the trans? Did you have clearance issues with the bracket that connects to the trans? It seems awfully tight down there. I just can't see how it is able to fit.