Removal (4.3L)

Turn ignition off. Disconnect negative battery cable. Remove air cleaner assembly. Reference mark spark plug wires at distributor cap for reassembly. Slightly twist all spark plug wires and ignition coil wire at distributor cap. Remove all spark plug wires and ignition coil wire at distributor cap by pulling on the wire boot.
Disconnect harness connector at base of distributor. Remove distributor cap retaining screws and distributor cap. See Fig 1. Using a grease pencil, mark position of the distributor rotor in relation to the distributor housing. See Fig 2. Make another mark on the intake manifold in relation to the mark made on the distributor housing.
Remove distributor hold-down bolt. Lift distributor upward while observing counterclockwise rotation of distributor rotor. Once distributor is fully removed, place a second reference mark on the distributor housing in relation to the distributor rotor position. See Fig 3.

Fig 1: Removing/Installing Distributor Cap Screws (4.3L)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Marking Position Of Distributor Rotor (4.3L)

Courtesy of GENERAL MOTORS CORP.

Fig 3: Marking Base Of Distributor (4.3L)

Courtesy of GENERAL MOTORS CORP.