Because the 134 cu. in. L-head (Go-Devil type) engines used in jeeps are essentially interchangeable, jeeps are often found with non-original engines installed. The casting numbers on an engine or block can be used to help determine what engine your vehicle has.   The casting numbers are part of the engine casting and are not stamped onto the metal of the block like a serial number. (See serial number page).  Generally, the block casting numbers are found on the right side of the engine block below the distributor. The block casting numbers are raised-not stamped. The head casting numbers are normally on the top of the head in the right front corner. Head casting numbers are either raised or recessed, but not stamped.
     It is helpful to know the casting number needed when searching for correct replacement blocks or heads for your MB or GPW.