To find the correct firing order, you must identify the engine in your truck (e.g., 3.9L V6, 5.2L V8, 5.9L V8). Once you know the engine, you can:
* Consult your owner's manual: This is the best source.
* Look for a sticker under the hood: Many vehicles have a sticker listing engine specifications and sometimes the firing order.
* Use a reliable online resource: Websites specializing in automotive repair information (like Chilton or Haynes) often have this data searchable by year, make, model, and engine.
Without knowing the specific engine, I cannot provide the firing order.