I just recently put a 351W and an AOD in my 81 Ford truck. I got the kickdown bracket/cable from lokar. Only mod I had to make for the cable was to add an L bracket on top of where the shifter linkage mounts to the tranny for the cable to go through. If you'd like I can take some pics for ya. Also, after you're done, make sure you set the pressure on the tranny with a gauge.
PS-Make sure you have the right flex plate for that motor/tranny combo.
John T.