The engine identification code is located in the VIN at the 8th digit. The VIN can be found on the Vehicle Certification Label and on the VIN plate attached to the instrument panel. See the Engine Identification chart for engine VIN codes.
There is also an engine code information label located on the engine. This label contains the engine calibration number, engine build date and engine plant code. On the 3.8L and 5.0L engines, the label is located on the side of the right rocker arm cover. On the 4.6L engine, the label is located on the front of the engine.