Engine codes
Thread Starter
2nd Gear
Joined: Jul 2022
Posts: 2
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From: Youngstown, Ohio
Engine codes
I bought a 1974 Corvette convertible last year, it had 57,000 miles and It was sold to me as matching numbers. Which I now found out is not true.When i steam-cleaned the engine and found these engine codes on the front of the motor. VO6106MJ 15S166511, so I believe it is from 1975. The problem is I can not find out what the MJ means have looked so many codes its making me dizzy. Anybody have an ideas? Because i am at a loss all I know is that it is a 350 probably an L48 if they were took the time to put another engine in it you think they would have put something with a little more horsepower.
Race Director
Joined: Oct 2000
Posts: 12,682
Likes: 3,135
From: Shamong, NJ
Are you sure you have the stamping right? "V" is the Flint engine plant "06" is June, and "01" is the first. There were some engine suffix codes that began with a "6", but they're always followed by an "X". I think what you identified as a "6" is more likely a "C", making the suffix code "CMJ". There is also the very slight possibility that someone stamped a "6" instead of a "C", but this is extremely unlikely, as mistakes like that were usually caught and "ground out".
CMJ had three different uses.
1) 74 4bbl, 350/160, with an automatic in police cars.
2) 75 2bbl, 350/145, with A.I.R. emissions and automatic in Chevelle's, Monte Carlo's & full size Chevrolet's
3) 76 2bbl, 350/145, with A.I.R. emissions and automatic in Chevelle's, Monte Carlo's & full size Chevrolet's.
The engine's likely a 75 based on the VIN, but a check of the casting date on the flange where the trans mounts, on the right rear side of the block will narrow it down further.
Welcome to the Forum!!!
CMJ had three different uses.
1) 74 4bbl, 350/160, with an automatic in police cars.
2) 75 2bbl, 350/145, with A.I.R. emissions and automatic in Chevelle's, Monte Carlo's & full size Chevrolet's
3) 76 2bbl, 350/145, with A.I.R. emissions and automatic in Chevelle's, Monte Carlo's & full size Chevrolet's.
The engine's likely a 75 based on the VIN, but a check of the casting date on the flange where the trans mounts, on the right rear side of the block will narrow it down further.
Welcome to the Forum!!!
Racer
Joined: Aug 2019
Posts: 451
Likes: 520
From: Chicago Burbs
I bought a 1974 Corvette convertible last year, it had 57,000 miles and It was sold to me as matching numbers. Which I now found out is not true.When i steam-cleaned the engine and found these engine codes on the front of the motor. VO6106MJ 15S166511, so I believe it is from 1975. .
As gbvette62 previously mentioned, this engine looks to be a 1975 2bbl, 350/145, with A.I.R. emissions and automatic from Chevelle's, Monte Carlo's & full size Chevrolet's
Wellcome to the Forum and please post some pics of your car. We love pics!
Last edited by '73and'75; Sep 22, 2023 at 08:28 AM.
