someone may add to this list, but you will need a turn signal/wiper/cruise control switch, speed sensor, regulator, and servo.
You will need to replace the existing switch.
You will also need a two piece speedo cable. The speed sensor connects between the two speedo cables, behind the dash cluster.
The regulator mounts on the lower dash panel under the steering wheel.
The servo mounts in the engine compartment and operates on vacuum to control the throttle.
Oh, and also the wiring harnes for the regulator.
87 Comanche, 4.0, BA10/5, D44
84 CJ7, 4.2, AX15 (Formerly T5)