Your '83 (like my '84) has a traditional distributor -- that means that it has, in addition to the rotor, all the hardware needed to (1) tell the ECU what position the crankshaft is at, with the help of the hall sensor, and (2) vary the timing of the spark in relation to engine speed and load (via the weights and advance or retard diaphragm).

Both tasks (1) and (2) are no longer the responsibility of the distributor in your '89 (like my '93's). The ECU knows about the crankshaft position from the Crankshaft Position Sensor (CPS) now located on the top of the bell housing and getting its reading from the flywheel (instead of the distributor shaft). And ignition retard or advance changes in timing are determined by an algorhythm in the ECU memory ("mapping" software). So the *only* task for the distributor is the same as a car in the 1910's or '20's (not typos), when engine timing was done manually with a lever on the steering wheel -- i.e., it only conducts the spark from the coil to the spark plugs, and thus only contains the rotor under the cap.

That's also why, as you might find, that the distributor is no long adjustable -- i.e., you cannot loosen a nut and rotate the body of the distributor, in order to change the basic timing in relation to, e.g., cylinder #1. There is (if it's like my '93) a block that prevents the distributor from being turned. Again, the ECU has full control over ignition timing.

Hope this helps.