727 no 3rd wont shift

your carb has got to have the mopar linage on it. adjust the kd rod so that front piece just fits on the carb stud, at the back of the slot. install the spring that holds it forward. go for a ride, if it doesn't shift the was you like it adjust the rod by the the front piece to make it longer. go for a ride and see how you like it. if not do it again until you're happy.