i dont know why but t/a's are showing both, cable and sensor. its looks like that yr. might have either. you need to call a dealership and ask them. if you have changed trans you'll have to know which sensor you need, may be dif. than the one in the trans. also you said you had put a carb. motor in ,have you changed your dist also? you computer will have to work to make the speedometer work. you gonna wish it was cable i belive. i just put a speedometer in a 1987 ss monte carlo and it had a cable.