Zappa56
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
C3 LT-1 engines were only made for 3 years: 1970, 1971 & 1972. Accordingly, the engine stamp pad codes for those engines were:
1970 - CTR, CTU & CTV (ZR1 option)
1971 - CJK, CJL
1972 - CKY, CKZ (ZRi option), CRS & CRT
If that engine doesn't have one of those codes in the engine stamp, it isn't 'real'. Not saying it couldn't be built like an LT-1 enigne...just that it was never one that came from the factory.
1970 - CTR, CTU & CTV (ZR1 option)
1971 - CJK, CJL
1972 - CKY, CKZ (ZRi option), CRS & CRT
If that engine doesn't have one of those codes in the engine stamp, it isn't 'real'. Not saying it couldn't be built like an LT-1 enigne...just that it was never one that came from the factory.
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4th Gear
Joined: Sep 2021
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Raffinger
No I am still here Raffinger. I was out of town. I will be posting pictures shortly. I am also new to being involved in a blog. And what is a real Corvette person? I have always loved the cars. I am learning more about them, and I appreciate the info. on the engine codes!
will be back
will be back
Safety Car
Joined: Feb 2012
Posts: 4,705
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From: Orlando FL
Thread Starter
4th Gear
Joined: Sep 2021
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Thanks
Oldgto, Thanks for your support! I’m just a regular guy trying to learn more about Corvette’s. I’m not a mechanic so am trying to get information on this forum which I understand is a great resource. I just purchased a1970 C3 completely rotisserie restored car.I’m going to try and get some info on putting in a tilt steering column. I will be posting pics. shortly on this car, they did a great job on it. The car is being shipped to me shortly.
Burning Brakes
Joined: Sep 2018
Posts: 1,002
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C3 LT-1 engines were only made for 3 years: 1970, 1971 & 1972. Accordingly, the engine stamp pad codes for those engines were:
1970 - CTR, CTU & CTV (ZR1 option)
1971 - CJK, CJL
1972 - CKY, CKZ (ZRi option), CRS & CRT
If that engine doesn't have one of those codes in the engine stamp, it isn't 'real'. Not saying it couldn't be built like an LT-1 enigne...just that it was never one that came from the factory.
1970 - CTR, CTU & CTV (ZR1 option)
1971 - CJK, CJL
1972 - CKY, CKZ (ZRi option), CRS & CRT
If that engine doesn't have one of those codes in the engine stamp, it isn't 'real'. Not saying it couldn't be built like an LT-1 enigne...just that it was never one that came from the factory.
1970 CTU CTK and CTV -(ZR1) CTU engines have the larger oil pan thus these cars were not avail with Power steering - like the ZR1's.
1971 CGZ or CGY (ZR1)
Race Director
Joined: Mar 2017
Posts: 11,906
Likes: 4,479
From: Virginia
I've found this site gives good results for code checking, for trim tags, engine stamp pads, casting numbers, etc.
http://corvettec3.ca
Here is the link to the engine codes:
http://corvettec3.ca/engines.htm
There are other things that identify an LT-1. If you are paying a premium, do your research and make sure they check out, too. Again, if it matters to you.
http://corvettec3.ca
Here is the link to the engine codes:
http://corvettec3.ca/engines.htm
There are other things that identify an LT-1. If you are paying a premium, do your research and make sure they check out, too. Again, if it matters to you.
Melting Slicks
Joined: Jan 2006
Posts: 3,180
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From: Sarasota Florida
Safety Car
Joined: Nov 2005
Posts: 3,532
Likes: 1,185
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
The corvette black book does list CTR as a 370hp LT1 for the 1970 model along with the other codes mentioned and with solid lifter cam and it came with a 010 block first year. Not saying that the black book is 100% correct, but it does list that code as well. 
Last edited by Buccaneer; Sep 28, 2021 at 08:14 PM.