C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Block numbers--help me decode possibilities?

Thread Tools
 
Search this Thread
 
Old Dec 4, 2013 | 12:39 AM
  #1  
DeadStang's Avatar
DeadStang
Thread Starter
Instructor
15 Year Member
 
Joined: Apr 2005
Posts: 191
Likes: 0
From: Oregon
Default Block numbers--help me decode possibilities?

The casting number is: 3970010
The stamping is: V0608CTB

When I try to search these, I get a bunch of different possibilities. But the combo search doesn't come up w/anything much definitive. Ideas?
Reply
Old Dec 4, 2013 | 12:42 AM
  #2  
63mako's Avatar
63mako
Race Director
20 Year Member
Liked
Loved
Community Favorite
 
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Default

Find the casting date on the bellhousing flange. That will narrow down the year then the CTB will determine the application for that year.
Reply
Old Dec 4, 2013 | 01:03 AM
  #3  
DeadStang's Avatar
DeadStang
Thread Starter
Instructor
15 Year Member
 
Joined: Apr 2005
Posts: 191
Likes: 0
From: Oregon
Default

Originally Posted by 63mako
Find the casting date on the bellhousing flange. That will narrow down the year then the CTB will determine the application for that year.
The number I found there was the 3xxxxx number...is there another place I should look (passenger side maybe)?
Reply
Old Dec 4, 2013 | 01:21 AM
  #4  
63mako's Avatar
63mako
Race Director
20 Year Member
Liked
Loved
Community Favorite
 
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Default

Drivers side rear near the casting number. Example: C270 is a March 27 1970 casting. 3970010 was used 1968 327 and 1969-1979 350 only.
http://www.nastyz28.com/sbchevy/sblo...a_close_button
3970010 (1969-1979 350) combined with CTB can only be a 1970 High performance 350 LT1 W/4speed. NICE!!!
http://www.nastyz28.com/gm-chevy-cod...s-suffix-3.php

Last edited by 63mako; Dec 4, 2013 at 01:36 AM. Reason: added link
Reply
Old Dec 4, 2013 | 08:41 AM
  #5  
Easy Mike's Avatar
Easy Mike
Team Owner
Supporting Lifetime
20 Year Member
 
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Default

CTB is not a Corvette engine code, but it could have been an LT-1. You will need the block casting date.


Last edited by Easy Mike; Dec 4, 2013 at 08:44 AM.
Reply
Old Dec 4, 2013 | 11:12 PM
  #6  
DeadStang's Avatar
DeadStang
Thread Starter
Instructor
15 Year Member
 
Joined: Apr 2005
Posts: 191
Likes: 0
From: Oregon
Default

I looked again for a casting date code near the 3xxxxxx number, but can't find anything else visible there. Does anyone have a picture of where exactly I might look when the engine is in the car? I tried a search but couldn't come up w/anything.
Reply
Old Dec 5, 2013 | 09:12 AM
  #7  
Mike7143's Avatar
Mike7143
Instructor
 
Joined: Jan 2013
Posts: 237
Likes: 0
From: Indianapolis Indiana
Default

Driver's side with block part number and pattern number:


Near top, driver's side still: I think that's the plant and shift clock and I'm not sure what the 3 is between the cast "screw heads"


And then here's on the passenger's side, the block cast date between the cast "screw heads" B252 which I believe is February 25th, 1972 for my March 13th 1972 coupe:


Someone please correct me if I'm wrong. So... 3970010 block from pattern 32 cast around 3pm during the 10am shift at the Tonawanda plant in Buffalo, NY on February 25th, 1972. I can't explain the cast 3 between screws near the shift clock casting.

Last edited by Mike7143; Dec 5, 2013 at 09:37 AM.
Reply
Old Dec 5, 2013 | 09:41 AM
  #8  
BKarol's Avatar
BKarol
Melting Slicks
Veteran: Army
20 Year Member
Liked
Community Favorite
 
Joined: Sep 2004
Posts: 3,223
Likes: 666
From: Northeast
Default

In an article I read there were 21 conveyors. In the 2nd pic the 3 would signify it went down conveyor #3.

In the last pic because of one flat head and one round head it was made on the 2nd shift.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

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

 Joe Kucinski
story-1

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

 Joe Kucinski
story-2

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

 Verdad Gallardo
story-3

Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

 Joe Kucinski
story-4

Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

 Verdad Gallardo
story-5

Top 10 Corvettes Coming to Mecum Indy 2026!

 Brett Foote
story-6

Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

 Michael S. Palmer
story-7

10 Revolutionary 'Corvette Firsts' Most People Don't Know

 Joe Kucinski
story-8

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-9

2027 Corvette vs The World: Every C8 vs Its Closest Competitor

 Joe Kucinski
Old Dec 5, 2013 | 09:43 AM
  #9  
Mike7143's Avatar
Mike7143
Instructor
 
Joined: Jan 2013
Posts: 237
Likes: 0
From: Indianapolis Indiana
Default

Originally Posted by karol
In an article I read there were 12 conveyors. In the 2nd pic the 3 would signify it went down conveyor #3.

In the last pic because of one flat head and one round head it was made on the 2nd shift.
Interesting note on the conveyors, never knew that. Regarding shift, does that mean 2nd shift started at 10am?

Also, I realized I have no idea what the T G N symbol is, I thought it was which plant it was cast at, but if it was Tonawanda I'd think it'd be pointing to the T? I know up front is the stamp position for engine assembly plant, but I assume that's the plant where the engine is finished (in my case V for Flint, MI) and then mates to chassis, i.e., assembly so St. Louis (12Sxxxxxx) for a 72. But the block would have been cast in Tonawanda I'd think?

Last edited by Mike7143; Dec 5, 2013 at 09:52 AM.
Reply
Old Dec 5, 2013 | 11:19 AM
  #10  
Mike Ward's Avatar
Mike Ward
Race Director
10 Year Member
 
Joined: Jul 2001
Posts: 15,892
Likes: 42
Default

Originally Posted by Mike7143
Interesting note on the conveyors, never knew that. Regarding shift, does that mean 2nd shift started at 10am?

Also, I realized I have no idea what the T G N symbol is, I thought it was which plant it was cast at, but if it was Tonawanda I'd think it'd be pointing to the T? I know up front is the stamp position for engine assembly plant, but I assume that's the plant where the engine is finished (in my case V for Flint, MI) and then mates to chassis, i.e., assembly so St. Louis (12Sxxxxxx) for a 72. But the block would have been cast in Tonawanda I'd think?
With very very few exceptions, all Corvette SBCs were cast and assembled at Flint. The casting date on this block has a single digit for the year which identifies it as a Flint block. Tonawanda used two digits for the year.
Reply
Old Dec 5, 2013 | 11:44 AM
  #11  
Mike7143's Avatar
Mike7143
Instructor
 
Joined: Jan 2013
Posts: 237
Likes: 0
From: Indianapolis Indiana
Default

Ahh. So the block was cast AND built in Flint, then shipped to St. Louis for install. So any ideas what the TGN pointer casting is?

Don't mean to hijack DeadStang, just thought I'd post pictures that may help you locate your casting date as well as help in identifying more details on your block as well as mine!
Reply
Old Dec 5, 2013 | 02:49 PM
  #12  
Easy Mike's Avatar
Easy Mike
Team Owner
Supporting Lifetime
20 Year Member
 
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Default

Originally Posted by karol
...In an article I read there were 21 conveyors. In the 2nd pic the 3 would signify it went down conveyor #3...
I've read the 3 indicates the mold used to cast the block.
Reply
Old Dec 5, 2013 | 04:00 PM
  #13  
Mike7143's Avatar
Mike7143
Instructor
 
Joined: Jan 2013
Posts: 237
Likes: 0
From: Indianapolis Indiana
Default

Originally Posted by Easy Mike
I've read the 3 indicates the mold used to cast the block.
I thought that was what the 32 was near the block number...
Reply
Old Dec 5, 2013 | 04:38 PM
  #14  
qtlow's Avatar
qtlow
Pro
15 Year Member
Active Streak: 120 Days
 
Joined: Feb 2008
Posts: 556
Likes: 13
From: C3 Forum, Colorado
Default

Originally Posted by Mike7143
So any ideas what the TGN pointer casting is?
The way alan71 once explain it was the TGN pointer designated which shift at the foundry cast the part. For example - daylight, twilight or night shift.

THREAD
Reply
Old Dec 5, 2013 | 04:41 PM
  #15  
Mike Ward's Avatar
Mike Ward
Race Director
10 Year Member
 
Joined: Jul 2001
Posts: 15,892
Likes: 42
Default

Originally Posted by Mike7143
So any ideas what the TGN pointer casting is?
No, but I'd like to start a new myth.

For many years the 010 and 020 numbers found under the timing cover on some blocks were mistakenly though to mean a high percentage of nickel and tin, making the block somehow 'better'. We now know that these numbers were the last three digits of the block casting number that the mold was used for 3970010 and 3970020 but the legend lives on.

I propose a new story that the TGN stands for Tin, Gold and Nickel. If anyone finds a block with the pointer at the G, it's made of pure gold and worth a million-squillion dollars.
Reply
Old Dec 5, 2013 | 04:52 PM
  #16  
BKarol's Avatar
BKarol
Melting Slicks
Veteran: Army
20 Year Member
Liked
Community Favorite
 
Joined: Sep 2004
Posts: 3,223
Likes: 666
From: Northeast
Default

Originally Posted by Mike7143
I thought that was what the 32 was near the block number...
Read Frank's explanation in Post #4:

http://forums.corvetteforum.com/c3-g...an-thanks.html
Reply
Old Dec 5, 2013 | 04:53 PM
  #17  
Alan 71's Avatar
Alan 71
Team Owner
15 Year Member
Active Streak: 120 Days
Community Influencer
Top Answer: 5
 
Joined: Sep 2006
Posts: 31,200
Likes: 4,287
From: Westminster Maryland
Default

Hi,
I agree about the D, T, and N indication, but I believe the pointer with the arrow and circle of dots wasn't indicating the time of day, (not 10 a.m.), but rather the hour count with-in the shift.
Regards,
Alan
Reply

Get notified of new replies

To Block numbers--help me decode possibilities?

Old Dec 5, 2013 | 05:18 PM
  #18  
BKarol's Avatar
BKarol
Melting Slicks
Veteran: Army
20 Year Member
Liked
Community Favorite
 
Joined: Sep 2004
Posts: 3,223
Likes: 666
From: Northeast
Default

Originally Posted by Alan 71
Hi,
I agree about the D, T, and N indication, but I believe the pointer with the arrow and circle of dots wasn't indicating the time of day, (not 10 a.m.), but rather the hour count with-in the shift.
Regards,
Alan
So would that be the 7th hour?

Last edited by BKarol; Dec 5, 2013 at 05:22 PM.
Reply
Old Dec 5, 2013 | 05:25 PM
  #19  
Mike7143's Avatar
Mike7143
Instructor
 
Joined: Jan 2013
Posts: 237
Likes: 0
From: Indianapolis Indiana
Default

Okay so the 32 is the pattern serial number, and a 3970010 block with pattern serial number 31? would have been cast at the same time with my 32 (Frank mentions pouring 2 at a time) from a mold number I don't know. As Frank put it, series XX patterns 31 and 32? Or perhaps it was incremental so pattern serial numbers 32 and 33 were in series XX. Not sure where Frank got the series (mold number) from.

As far as the clock goes, I just got that from nastyz28, but now that I re-read it that makes more sense. So it looks like my block was cast during the twilight or 2nd shift, 7 hours into the 10 hour shift. So if one knew when 2nd shift started, you could get the hour of day it was cast as well. No wonder searching Google for TGN was useless, it's apparently a D

qtlow's link was helpful, wish I had found that earlier!
Reply
Old Dec 5, 2013 | 05:31 PM
  #20  
Mike7143's Avatar
Mike7143
Instructor
 
Joined: Jan 2013
Posts: 237
Likes: 0
From: Indianapolis Indiana
Default

Originally Posted by Easy Mike
I've read the 3 indicates the mold used to cast the block.
Or if this is the case, and it's not the conveyor number, then it'd be pattern serial number 32 from mold/series 3?
Reply



All times are GMT -4. The time now is 07:50 PM.

story-0
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-1
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-2
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
story-3
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-4
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-5
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-6
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-7
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-8
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-9
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE