C3 Vin Code

[Jerry G.]

Does anyone know if there is a letter in the VIN code that indicates what engine a vehicle originally came with? I have heard that a big block will have a different letter than a small block and an LT1 has a unique code also. Can anyone verify this? Thanks Jerry

[Harmon C.]

Re: C3 Vin Code

For 1972 and later the VIN. has the engine identifed.

[Jim T.]

Re: C3 Vin Code

Reference LT-1 and VIN number difference. The last year of the LT-1 1972 did have a letter in the VIN number. The LT-1 VIN number in 1972 would have a L as the fifth digit. The standard engine VIN number would have a K and the 454 would have a W. To bad this was not used earlier, some people would have less money in selling their cloned Corvettes.

[artarmstrong]

Re: C3 Vin Code

Jerry, My VIN records only go back to 1972 and they show an engine code (letter) in the 5th digit position from the left. The VIN break down chart that identifies what the "letters" mean, in the engine position, shows the entire GM engine line up with, C.I.D.,N.H.P.,CARB, EX, and which division(s) built a given engine.
So the answer to you question is Yes, but you have to have the VIN break down chart, which I'm pretty sure is in the front of all the Service Manuals, in order to decipher the letter codes.
This applies to MY's from 1972 to present in one form or another with some variations.

Art

[Jerry G.]

Re: So how do I avoid a clone?

Are there some major things like the frame or inner fender panels that I can look at to spot a clone. ie Physical evidence. I'm looking for a 70-72 BB car. Jerry

[Joe L.]

Re: So how do I avoid a clone?

Jerry-----

Original documentation is the only relatively foolproof way to avoid a "clone" absent the VIN-encoded engine system used only from 1972 onward.

For a 70-72 original big block Corvette, look for the following:

1) presence of factory-type rear stabilizer bar (only big blocks had these for during the big block years)

2) presence of cap-type rear stub axles (some 71 and 72 small blocks may have had these but, for the most part, they were a big block only item through 1972. After 1972, many small blocks had them)

[Jerry G.]

Re: Thanks Joe Sounds like same for C2 *NM*

[Jim T.]

Re: So how do I avoid a clone?

Some or at least one 70 small block had the cap style rear stub axles. Mine came this way with turbo 400 auto.

[Jerry G.]

Re: Are there fuel line diff in BB vs SB? *NM*

[Joe L.]

Re: Are there fuel line diff in BB vs SB?

Jerry-----

For 1970-72, both big block and small block used a fuel return line (except LT-1). So, as far as that feature goes, there was no difference between big blocks and small blocks. However, I believe that the configuration of the forward end of the chassis fuel lines was different for big blocks and small blocks. One of these days, I need to study and quantify this difference as it is a very important and relatively fool-proof means of distinguishing between original big block and small block cars. That's because the chassis fuel line is a lot more difficult to change than other big block/small block unique features or "tell-tale" signs.

[Erv Schlepp]

Re: So how do I avoid a clone, knowledge or Docs

Jerry:

If your do not have documentation back to the original owner as I have which includes the Manufacturers Statement of Origin (MSO),there are still ways to tell. The 1970 BB has many different parts from a small block and the LT-1. Most of the time a clone will not have all the correct parts. If you look in the AIM it has sheets for the 454 option. Many parts are unique to the BB corvette including differences in options used with both small and big block corvettes.

If you are looking at a specific car note the options an then review the AIM and you will find differences that only a exceptional clone would have correct. If it is a 70 I know for a fact there are many differences. A good source to talk to would be our NCRS Editor. Terry wrote the judging manuals for 70 - 72 and has a Duntov 70 LT-1.

If you find something and it is a 70 you can email me and I,ll check anything you would like to know relative to my 70 BB.

Good luck Jerry