The 7.4L engine serial number is located on the engine block and the right cylinder head (1). The engines optional serial number can be located at the left corner of the cylinder block (2).
The engine serial number for the Caterpillar® 3126 diesel engine is on a metal plate on the upper left rear corner of the engine block.
The engine unit number or date code is stamped on the engine block.
Engines are stamped with an nine digit engine identification number.
