I have a 360 motor and 727 trans out of a mid 70's dodge van. It came with the stock kickdown rod. It is attached at the transmission with a cotter pin to a separate arm that moves parallel to the trans. It swings from front to back. I have a high rise intake and a carter AFB. The carburetor has provision for attaching a kickdown to the lower part of the throttle linkage.

is the kickdown lever that attaches to the carb the slotted kind?

yes, and it threads onto the rod to allow adjustment

Carb wide open trans lever almost all the way to the rear.

hopefully it is running parallel to the engine........ un hook the lever from the carb, make sure the trottle is forward (idle), pull the kickdown forward and screw (or unscrew) the slotted 'head' of the lever until it just clears the lever part of your throttle linkage (the furthest back point of the slot). that should get you to a 'ballpark' area where you can take out and tweek it until you get it to down shift where you want