The only function of the cable on a 350 is for forced 3-2 downshifts (hence the name "kickdown cable"). TH 400's have an electric kickdown solenoid. Both of them control shift points with a vacuum modulator. Virtually all automatic transmissions have three pressures- - - -main line pressure that applies clutches, bands, etc., governor pressure that reflects vehicle speed, and throttle pressure, controlled by either a vacuum modulator or mechanically with linkage or a cable connected to the gas pedal. Governor pressure opposes throttle pressure, causing the trans to shift up or down according to speed and engine load. That was the way things worked for 50-something years, until computers, driveshaft speed sensors, throttle position sensors, and solenoid-operated shift valves got into the mix. Now shift strategies are a whole new ballgame, determined and controlled by a bunch of computer code writers! Automatic transmissions are still smarter than all drivers, and most mechanics! It's virtually impossible to get one in the "wrong" gear for very long, like happens frequently with a stick shift.
Jerry
