my 90 dakota with a 2.5l and 5 spd manual has no cruise. what would it take to put cruise in?

 

The cruise control stick inside, the wiring between, the cruise servo, the underhood wiring, and the cable from the servo to your throttle body.

Not sure if it was ever offered on a 2.5L for 1990, though; your ECU may not have the code to support cruise.

RwP