My 70 Coupe has a weird location for the engine codes and was wondering if there was any kind of explaination behind it. The plate at the front of the block usually (from what I've seen) has a portion of the VIN on the left hand side (which would be 70S400307) and on the right side has the date and engine id (V1218CTH). But my engine has the engine date and id info on the right side, but no VIN id on the left hand side of the plate. There is however, the VIN numbers down by the oil filter on the driver's side of the car.
Is there a reason or explanation for that?

 

Patrick,

That is the method of stamping for Camaros at the Van Nuys plant in California during the 1969 model run.

 

If that is the case, then how did this particular corvette information get stamped onto this motor in the style of the 69 camaro? I'm confused. Is there a possibility that this engine does not belong in this car?

 

According to this site
http://www.camaros.org/drivetrain.shtml#PadStamps

and this picture
http://www.camaros.org/images/decode...p_location.jpg

It looks like the 69 camaros were stamped the same way in the same location just in the opposite order.

But then there is this "alternate vin location" picture
http://www.camaros.org/images/decode...p_location.jpg

So what could this all mean?

 

Patrick,

I would pose your question over on the ncrs.org website. There are some very knowledgeable individuals on '70 to '72 small block Corvettes.

 

Your description sure sounds like a Camaro motor. Did the Camaro motors have the same casting date style as the Corvette ("9" instead of "69"). Tonawanda vs. Flint? Your Camaro info links do not detail the casting year layout.

CTH sure sounds like Corvette 350/350 though.

Does the VIN on your block match the windshield pillar VIN?

What is your block casting number?

 

This section shows that the partial vin casting on the blocks had just the 7 for 67 so I think that answers that question. And also gives a brief description of why they moved the vin to the oil filter area.

Engines
For most 67-69 Camaros, the partial VIN was stamped on the engine pad near the engine assembly code. In 1967, generally only the Z28 and SS engines had the partial VIN's stamped. In 1967, this code consists of the sixth through the thirteen characters of the full VIN, e.g. 7N123456. For 1968 and on, the drivetrain partial VIN's became a federal requirement. In 1968 and 1969, the code was changed to add the first digit of the full VIN, e.g. 19N512345, per the federal law.

During the mid-1969 model year, the partial VIN for V8 engines was stamped near the oil filter, due to the '69 model year change in location of the alternator to the passenger side (covering the engine stamp pad). The block in this area is raw unmachined casting which makes this stamp difficult to see. The Norwood plant moved the VIN to the oil filter in the December 68 timeframe. Los Angeles was not as consistent and the VIN location varied during the year.

Yes the engine vin stamp matches the windshield vin stamp as well as on the registration / title. The date code on the engine is 1218 which would go wiht the A06 trim plate date as well right? The engine is usually a week or so behind the trim date?

I will post over at the other site as well. Thanks

 

this is the response i received from the ncrs.org site. just thought i would pass it on for curiosity sake, and I'll update and more detailed info that I get.

This anomaly was found on early 1970 Corvettes, yours being the second that I have seen in over 22 years of looking at these cars. According to the information we have this style of stamping occurred during the first 3 to 5 days of 1970 production

 

You should be okay. #307 would have been the second or third day of production.

 

I am the current owner of the car in question from this 2007 post . I've attached photos of the original engine VIN and engine code stamps. I had never heard of the alternate stamp location next to the oil filter until purchasing this car . First day of 70 Corvette production was January 5th , build code for my car VIN 4000307 is A06 - January 6th , second day of production.
It is estimated that this location was only used for a week . This was first done on 69 Camaros because the new location for the alternator was blocking access to the machined pad on front of the head. My assumption is that this practice was abandoned because of the cast iron surface making it hard or impossible to get a readable stamp .
Fortunately , mine is easy to read on both the engine and transmission .

 

Wow, 17 years later.

Start a new thread if you want to continue the topic.