The 3.0L Ford engine, depending on the specific application (truck, car, etc.) and year, can have different cylinder configurations. There's no single answer.
It's a V6 engine, meaning the cylinders are arranged in a V-shape, typically with a 60-degree angle between the cylinder banks. Each bank would then have three cylinders.
To know the precise cylinder location and firing order, you'd need to specify the exact year, make, and model of the vehicle the engine is in. Then you can consult a repair manual or online resources specific to that engine.