C3 General General C3 Corvette Discussion not covered in Tech
Sponsored by:
Sponsored by:

Engine Id

Thread Tools
 
Search this Thread
 
Old Oct 20, 2025 | 10:16 AM
  #1  
Mgodoy71's Avatar
Mgodoy71
Thread Starter
Heel & Toe
All Eyes On Me
Photogenic
Liked
 
Joined: May 2024
Posts: 20
Likes: 8
From: Tarpon Springs, Florida
Default Engine Id

Found this above my oil filter. Anyone know how to decipher this 010 020 147 code?
Reply
Old Oct 20, 2025 | 02:22 PM
  #2  
Bikespace's Avatar
Bikespace
Race Director
Liked
Loved
Community Favorite
Top Answer: 1
 
Joined: Mar 2017
Posts: 11,949
Likes: 4,507
From: Virginia
Default

What does the engine stamp pad say? That's a lot easier to decipher.
Reply
Old Oct 20, 2025 | 02:31 PM
  #3  
MelWff's Avatar
MelWff
Race Director
20 Year Member
Liked
Loved
Community Favorite
 
Joined: May 2006
Posts: 18,734
Likes: 2,582
Default

Originally Posted by Mgodoy71
Found this above my oil filter. Anyone know how to decipher this 010 020 147 code?
That's not how you ID the engine.
Look at the pad in front of the passenger side cylinder head located on the block.
Reply
Old Oct 20, 2025 | 02:59 PM
  #4  
Mgodoy71's Avatar
Mgodoy71
Thread Starter
Heel & Toe
All Eyes On Me
Photogenic
Liked
 
Joined: May 2024
Posts: 20
Likes: 8
From: Tarpon Springs, Florida
Default

Yes, I know. Just curios what these mean.
Reply
Old Oct 20, 2025 | 03:49 PM
  #5  
avalonjohn's Avatar
avalonjohn
CF Community Team
15 Year Member
Veteran: Marine Corps
Liked
Top Answer: 1
 
Joined: Mar 2007
Posts: 9,329
Likes: 359
From: Delaware
St. Jude Donor '25
Default

Originally Posted by Mgodoy71
Yes, I know. Just curios what these mean.
Trying to research and help. Is your block an 010? I was reading something that said the first set may be the block casting number abbreviation (separate from the full number).

I am reading that the 010 (350) and 020 (307) shared the same mold when cast. Maybe the 010 020 are a reference to that? Still looking for the other number meaning but I did notice it seems cast further down spacing wise than the top sets.
Reply
Old Oct 20, 2025 | 04:58 PM
  #6  
Nowhere Man's Avatar
Nowhere Man
Team Owner
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2003
Posts: 54,106
Likes: 9,422
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
Default

Originally Posted by avalonjohn
Trying to research and help. Is your block an 010? I was reading something that said the first set may be the block casting number abbreviation (separate from the full number).

I am reading that the 010 (350) and 020 (307) shared the same mold when cast. Maybe the 010 020 are a reference to that? Still looking for the other number meaning but I did notice it seems cast further down spacing wise than the top sets.
yes the same pattern. Chevy did the same thing for 327 and 283 blocks
Reply
Old Oct 20, 2025 | 05:02 PM
  #7  
Mgodoy71's Avatar
Mgodoy71
Thread Starter
Heel & Toe
All Eyes On Me
Photogenic
Liked
 
Joined: May 2024
Posts: 20
Likes: 8
From: Tarpon Springs, Florida
Default

Yes 3970010 in a 1971
Reply
Old Oct 20, 2025 | 07:33 PM
  #8  
BKarol's Avatar
BKarol
Melting Slicks
Veteran: Army
20 Year Member
Liked
Community Favorite
 
Joined: Sep 2004
Posts: 3,225
Likes: 667
From: Northeast
Default

Urban myth :
010= 1 % additional tin
020= 2% additional nickel
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Oct 20, 2025 | 07:51 PM
  #9  
Nowhere Man's Avatar
Nowhere Man
Team Owner
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2003
Posts: 54,106
Likes: 9,422
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
Default

Originally Posted by BKarol
Urban myth :
010= 1 % additional tin
020= 2% additional nickel
that is the myth that needs to die.
Reply
Old Oct 20, 2025 | 07:51 PM
  #10  
69L88's Avatar
69L88
Melting Slicks
15 Year Member
Veteran: Army
Liked
Community Favorite
 
Joined: Nov 2006
Posts: 3,410
Likes: 1,821
From: Apple Valley, MN
Default

Overheard in the foundry department- “Hey Charlie, let’s set a few random numbers in the mold. 60 years down the road, it’ll drive the collectors nuts trying to figure them out”.
Reply
Old Oct 20, 2025 | 08:26 PM
  #11  
Nowhere Man's Avatar
Nowhere Man
Team Owner
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2003
Posts: 54,106
Likes: 9,422
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
Default

Originally Posted by 69L88
Overheard in the foundry department- “Hey Charlie, let’s set a few random numbers in the mold. 60 years down the road, it’ll drive the collectors nuts trying to figure them out”.
its the last three digits of casting numbers
Reply
Old Oct 21, 2025 | 07:56 AM
  #12  
Rebelyell's Avatar
Rebelyell
Drifting
 
Joined: Jun 2025
Posts: 1,715
Likes: 597
Default

I'm typically much more interested in block casting dates, block casting numbers; same for heads and how All those square with block stamp pad.
Reply
Old Oct 21, 2025 | 11:33 AM
  #13  
69L88's Avatar
69L88
Melting Slicks
15 Year Member
Veteran: Army
Liked
Community Favorite
 
Joined: Nov 2006
Posts: 3,410
Likes: 1,821
From: Apple Valley, MN
Default

Originally Posted by Nowhere Man
its the last three digits of casting numbers

The 010 may or may not be a coincidence (assuming it’s a 3970010 block) but how do you square the 020 and 147 numbers?
Reply
Old Oct 21, 2025 | 11:40 AM
  #14  
Alan 71's Avatar
Alan 71
Team Owner
15 Year Member
Active Streak: 120 Days
Community Influencer
Top Answer: 5
 
Joined: Sep 2006
Posts: 31,272
Likes: 4,362
From: Westminster Maryland
Default

Hello mg71,
I can't help with cast numbers or letters.....
so how about a little trivia?????
Regards.....

What was the purpose of the 'freeze plugs' ?





The blocks were cast in sand molds.
The blocks were "shook" to get the sand out and then the plugs were installed.
Remember the small block engines for all Corvettes and for other Chevrolet car lines were built at the Flint engine plant....at a rate of 5000 engines per day (2 shifts).
All the info is from John Hinkley.
Reply
Old Oct 21, 2025 | 11:49 AM
  #15  
Mgodoy71's Avatar
Mgodoy71
Thread Starter
Heel & Toe
All Eyes On Me
Photogenic
Liked
 
Joined: May 2024
Posts: 20
Likes: 8
From: Tarpon Springs, Florida
Default

Exactly! And these are cast along with block not a tag or manually applied as with VIN. Killing me!
Reply
Old Oct 21, 2025 | 12:03 PM
  #16  
Nowhere Man's Avatar
Nowhere Man
Team Owner
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2003
Posts: 54,106
Likes: 9,422
From: Sitting in his Nowhere land Hanover Pa
2024 C2 of the Year Finalist - Unmodified
2015 C2 of Year Finalist
Default

Originally Posted by 69L88
The 010 may or may not be a coincidence (assuming it’s a 3970010 block) but how do you square the 020 and 147 numbers?

020 is the last three digits of a 307 block Not sure on the 147 but they used the same casting sand pattern the casting number on the bellhousing flange numbers could be changed out unlike these numbers
Reply

Get notified of new replies

To Engine Id





All times are GMT -4. The time now is 07:35 PM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE