Tune-Up - V6: Adjustments: Distributor

Federal 4.3L models are equipped with Delco High Energy Ignition (HEI) distributors. All 2.8L models are equipped with Delco HEI-Electronic Spark Timing (HEI-EST) distributors. California models equipped with 4.3L carbureted engines are equipped with Delco HEI-EST distributors with Electronic Spark Control (ESC).

Fig 1: 2.8L Firing Order & Timing Marks

Fig 2: 4.3L Firing Order & Timing Marks