Engine code for C3 (1975)

[Kelly Hess]

Reading yesterdays posting on engine codes, the info was pasted that L = L48 and X = L82. My VIN code is J. The title lists 1Z37 (post 73) J (?) 5 (1975) and model Z37J. Can anyone help me with the J code. The car has matching #'s and I am in need of knowledge.

Thanks, Kelly

[artarmstrong]

Re: Engine code for C3 (1975)

Kelly, All the 1975 VIN's will have a "J", which stands for 350 DISP and that's all the further the engine code is broken down in the VIN as there was only a 350 offered in 1975. The L82 was the only optional engine choice for 75 and of course it is a 350 also.

Art

[artarmstrong]

oops.........................

I'm sorry Kelly, I don't know what I was thinking, I really should check things first---ignore the above, it's wrong and I can't delete it.

YES, The L82 will have a "T" for the optional engine.

Art

[Michael W.]

In addition-

1= Chevrolet
Z= Corvette
37=Coupe
J= L-48 (base engine)
5= model year
S= St. Louis assembly plant
remainder of the VIN is the sequential serial number of the car.

[Duke W.]

Re: In addition-

Actually, the reamainder of the VIN is the production sequence number plus 100,000. Job one carried a sequence number of 100001.

Duke

[Michael W.]

Not true for 1975

or 1973 thru 1981 for that matter, except for the Pace cars. Job one in each of those years carried the number 400001.

See, that Monterey sunburn didn't fry everything in my head after all!

[Duke W.]

Re: Not true for 1975

I'm going by the VIN breakdown definitions in the P&A catalog. Perhaps Kelly can resolve this by verifying the first digit of his sequence number.

Duke

[artarmstrong]

Re: Not true for 1975

Duke, I can verify it-----Mike is right, the 1973 thru 1981, except for the Pace cars, carried the vin number 400001.

Art

[Duke W.]

Re: Not true for 1975

Okay, I'm converted! Know why GM started with 400001 instead of 100001, like on the other model lines?

Duke

[artarmstrong]

Re: Not true for 1975

Joe,I used to know---but crs is setting in and I can't recall.

To further clairfy the 1973 thru 1981 vin's, in 1973 vin plates 424001-428000 were lost somewhere within GM and therefore were never used.
For 1981 both 400001 and 100001 were used. 31626 vehicles were numbered with 400001 that were built in St. Louis and 8995 vehicles were numbered with 100001 that were built in BG.

Art

[Craig S.]

Re: Not true for 1975

Duke - well, besides all my postings about midyears, I do have a 74 too....it is 1Z37T4S406823 (burned in my memory, my first purchased car). There lurks the 4.....Craig

[Duke W.]

Re: Not true for 1975

Art, I'm DUKE! Take your medication.

Somewhere I recall reading that the first digit in the sequence number - 1, 4 or whatever - is a "control number" or something like that. Does this jog your memory?

Duke

[John H.]

Re: Not true for 1975

Duke -

The first digit (of the last six) was arbitrarily chosen by carline and plant and that's what the plant was told to use. When the Federally-mandated 17-digit VIN started in 1981, one of the first eleven digits (can't remember offhand which one) was designated as a "check digit", which was assigned based on a "confidential" algorithm so law enforcement could spot a bogus VIN.

[Art A.]

SORRY Duke..................................

I'm ok now, got the meds in my system.

I had tried to respond to you last post awhile ago, but my cookies somehow got corrupted---I hope its back to normal.

Anyway since then John responded..............
"Duke -

The first digit (of the last six) was arbitrarily chosen by carline and plant and that's what the plant was told to use. When the Federally-mandated 17-digit VIN started in 1981, one of the first eleven digits (can't remember offhand which one) was designated as a "check digit", which was assigned based on a "confidential" algorithm so law enforcement could spot a bogus VIN. "

........... and he is right.

The "check digit" is in the 9th position.

Art

[John H.]

Re: SORRY Duke..................................

BTW, the "confidential" nature of the check digit lasted about three days; several of the A.I.M.'s of the period even had charts on how to create it correctly based on the other digits in the VIN. Duh!