Some engine machining operations (decking) will obliterate the engine ID.Įngine ID Code Example: V0101CLJ - (V = Plant, 01 = Month, 01 = Day, CLJ = Engine Suffix Code)Īnother example: T0830CTY - (T = Tonawanda, 08 = August, 30 = 30th day, CTY = 1970 396 Camaro, 375 hp, 11.0:1, TH400) The engine assembly date must precede the car build date (often by a few days), otherwise something is amiss. The suffix portion tells you the original application, vehicle model, engine RPO/ transmission / horsepower, etc. The prefix portion of the ID code tells you the engine assembly plant code, and the engine's assemblyĭate (for example, 0701 = July 1st.no year is indicated). Six Cylinder: Passenger side of the block behind the distributor. Often hidden by the alterator.īig Block Chevy: Machined pad in front of the passenger side cylinder head or above timing chain cover. Small Block Chevy: Machined pad in front of the passenger side cylinder head. The location of this code depends on the type of engine, typically as follows: Everything else lines upĪll engines are stamped with an engine ID code, consisting of assembly plant code, production 1973 - eliminates every other possiblity. This is why I looked at the VIN code 1st. That eliminates the 400 and 305 possibilities.Īs you can see - codes are reused and/or they span years. So when the arguement over 305, 350 or 400 comes up. In 1987 CLJ is a 305 L69 in a monte carlo, or in 1971 it's a 400 from a

ONE NOTE: Casting #'s will trump the code on a descrepancy. And/or - you can check dates to make sure everything came together when original.

Other pieces and parts should have been on it, and check those casting #'s. Once you identify something - like the above vette block, then you can conclude what The thing is - you need more than the casting #. If you're trying to buy a 350 and you see this thing laying on the ground, then there it is. trying to decode '3970010' is almost pointless. but using these 2 things, I already know EXACTLY what this was.ġ970. I can GUESS the casting # is 3970010 and check casting dates, etc. If that happens to be the vehicle this engine is currently sitting in they 'match'. Knowing this, I can conclude the original vehicles VIN is or was 1Q87T3N132794. So I'm dealing with something from a 1973 Camaro.ĬLJ in 1973 is a 245 horsepower 350 used in a Z28 Camaro mated to a manual transmission. I know Norwood built Camaros - among other things. Quickly from the partial vin I know this is a Chevy (1) 1973 model year (3) built in Norwood Ohio (N).ġ32794 is the unique vehicle serial number (to match against vehicle VIN). I can see the partial VIN (13N132794) and the engine code (V0112CLJ).

Decoding engine serial numbers