To get the CID, you need to convert liters to cubic inches. The conversion factor is approximately 61.02 cubic inches per liter. Therefore, a 5.4-liter engine is approximately 5.4 liters * 61.02 in³/liter ≈ 329.5 cubic inches.
However, keep in mind that this is an approximation. The actual CID stamped on the engine block might be slightly different.