All engine assemblies carry an engine identification number. On all eight cylinder engines, the E.I.N. Is on a pad located on the right side of the block to the rear of the engine mount. In addition to the previously covered E.I.N., each engine assembly carries an engine serial number which must be referenced when ordering engine replacement parts. On 318 C.I.D. 8 cylinder engines, the engine serial number is located on the left front corner of the block, below the cylinder head.
Mopar engines are divided into several groups: The slant 6's:170 and 198 cubic inch are known as 'G' engines The slant 6: 225 cubic inch is known as the 'RG' engines. Hirens Bootcd 10 4 H33t Next G Das. The 'wide' block 318 cubic inch (1958 to 1966) is known as the 'A' engine. The small block V8s 273, 318, 340 and the 360 cubic inch are known as the 'LA' engines. The 361, 383 and the 400 cubic inch engines are known as 'B' engines. The 413, 426 wedge and the 440 cubic inch engines are known as 'RB' engines (raised block) The 426 cubic inch Hemi is in a class by itself. To locate your casting number, look on the side of your block and compare it to the chart below for engine Id, the date may also be stamped on the block by the casting numbers.
There is also the id stamp on the engines: On the slant six engines it is located just below the cylinder head on the passenger side of the block. On the 'A' and the 'LA' engines it is stamped on the drivers side front of the block just below the cylinder head. On the 'B' engines it is stamped on the top of the block near the distributor. On the 'RB' engines it is stamped on top of the block forward of the intake manifold on the drivers side. The stamps may include the engine size and also a series number for the year. A=1965.B=1966.C=1967.D=1968.E=1969.F=1970.G=1971.H=1972.J=1973.4?=1974 There could also be a stamping 'HP' or 'HP2' designating High performance.