The date code and casting numbers are mainly for identification and quality-control purposes. This pad is actually an extension of the block deck surface.But first, let’s give you a little background on why the numbers are there. V8 – On both small- and big-block V8s, the engine ID codes are found on a machined pad on the front passenger side of the block just below the head. L6 – The engine identification codes are located on a machined pad on the right (passenger) side of the block behind the distributor. These numbers may not be found on early (pre-’65) engines.įor the sake of clarity, we’ve broken down the locations by engine type and code/number type. was included mainly as a theft deterrent (it’s a means of linking a particular engine to a car in the case of theft).
The number included a division identifier (1 = Chevrolet), the last digit of the year model, a code for the final assembly plant and the last six digits of the chassis serial number (the sequence number). was stamped into the block by the final assembly plant. Additionally, after the engine was earmarked for installation into a specific car, an engine V.I.N. These were stamped on the engine at the assembly plant (the engine assembly plant, not the car assembly plant), and identified the date of assembly, which particular displacement/horsepower combination the assembly is and what chassis it was to be installed in. Again, other components carry casting numbers, some within the engine itself, but we’re concerned only with those that can be seen without major disassembly. Another important set of numbers is the engine plant code/engine ID number. Casting numbers are also found on the block, heads, and intake manifold. Date codes are found on the block, heads and intake manifold (along with many other areas and components throughout the car, but for the purposes of our discussion here, we’re not concerned with those). Casting numbers also identify specific “families” of components.įor example, cylinder heads with the same casting numbers will have similar applications, although some of the finishing details, like valve sizes, may vary. Through the casting date, the day/night shift indicator and, on some components, the “clock” position, it’s possible for Chevrolet to pinpoint within an hour or so when a specific component was cast. WHAT ARE THEY?īut first, let’s give you a little background on why the numbers are there. In the next few paragraphs, we’re going to tell you where to find the various codes that matter for the engine. The engine components themselves (block, heads and intake) will have various casting numbers, date codes, and an engine identification code, all of which are important and should be correct if the car is to be considered numbers matching. These include the engine, transmission and rear-axle assembly.
A true “numbers-matching” muscle car is always worth more than one with unoriginal drivetrain parts, so the question is, how do you determine what is and is not matching numbers? It’s really not that difficult, you simply need to know where to look and how to read what you find. In a nutshell, matching numbers refers to the various codes and dates found on all the major driveline components. Usually there’s a hefty price tag associated with those numbers as well. You’ve seen and heard it before: “Numbers matching”.
The last motor series was the 700 series, and a 500 series was produced as a replacement motor around the same time.OR, HOW TO TELL A NOVA 396 FROM A DUMP TRUCK 366… The 300 series motor was produced from 1950 to 1951. If you need NOS parts I have a large supply, and if you want cheaper reproduction parts I can advise you where to locate them.
Not sure what you mean by "Rochester" frame, but most had the Schwinn frame, but Cleveland welding was also a popular choice if it had the springer front forks.
The 300 series motor is worth more than the earlier "H" & "J" because it has 3 HP instead of 2.5 HP. The motor normally had a carter carburetor, and the numbers on the bottom of the cylinder simply tell which series of cylinder on the motor. If the numbers are 300,000 and up it was a Whizzer produced bike & motor, IE Pacemaker. The numbers from 350,000 and up means it was a kit and could end up on any bike. The numbers mean it is a 300 series motor.