The firing order for a 1990 Chevy G20 depends entirely on the engine it has. The G20 came with several different engine options (e.g., small-block V8s, a V6, and possibly even a diesel). You
must identify the specific engine (e.g., 4.3L V6, 5.0L V8, 5.7L V8, etc.) to determine the correct firing order.
Once you know the engine size and type, you can find the firing order in your owner's manual or online through a reliable source like a repair manual specific to your vehicle's year, make, model, and engine.
