Correct tranny ?
Thread Starter
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Correct tranny ?
Hi
I own a 68 convertible BB auto.
VIN is 16530 , so an April car.
All I find on it's tranny is following on a riveted metal tag :
427
CL 68 1875
How do I find out if it is a numbers matching tranny for this 390 HP car ?
Günther
I own a 68 convertible BB auto.
VIN is 16530 , so an April car.
All I find on it's tranny is following on a riveted metal tag :
427
CL 68 1875
How do I find out if it is a numbers matching tranny for this 390 HP car ?
Günther
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,923
From: Washington Michigan
That code says it's the correct transmission type for the 427, the correct model year ('68), and was made on the 187th day since '68 production started (in February), so it lines up well with your April car. The VIN derivative should be stamped on a raised boss on the forward passenger side of the case or on the driver's side flange where the trans bolts up to the engine. 
Thread Starter
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi
Thanks. So 1875 is the 187th day. What does the 5 stand for ?
I could not locate any boss with a stamped VIN yet. Have to keep on looking. Unfortunately, a chrome TURBO 400 oil pan is installed. Guess this is not original and might hyde the VIN.
Günther
Thanks. So 1875 is the 187th day. What does the 5 stand for ?
I could not locate any boss with a stamped VIN yet. Have to keep on looking. Unfortunately, a chrome TURBO 400 oil pan is installed. Guess this is not original and might hyde the VIN.
Günther
Race Director
Joined: Apr 1999
Posts: 10,866
Likes: 717
From: Beverly Hills/Pine Ridge Florida
Your THM 400 tag should look like this.
68 XXX
C L
CL 68 YYYY
Most tags are yellow, some are blue.
The codes are as follows:
CK SB
CL BB hydraulic lifter
CK BB solid lifter
These codes indicate the governor/kickdown inside that dictates shift point RPM of the trans.
On the first line of the tag is the year, then XXX is a Julian Date
Second line C L THM type
Third line Trans type again, year, YYYY= SN of trans
The dates for 68 cars begin on Jan 1 of 1967, yes 1967. SO, you have 365 days plus the days in 68.
The 1875 number is the SN of the trans, and has nothing to do with the Julian date.
What are the other numbers on the first line of your tag?
BTW, I've never seen a VIN derivitive stamped on a THM 400, BUT, I'm really not sure. Chuck
68 XXX
C L
CL 68 YYYY
Most tags are yellow, some are blue.
The codes are as follows:
CK SB
CL BB hydraulic lifter
CK BB solid lifter
These codes indicate the governor/kickdown inside that dictates shift point RPM of the trans.
On the first line of the tag is the year, then XXX is a Julian Date
Second line C L THM type
Third line Trans type again, year, YYYY= SN of trans
The dates for 68 cars begin on Jan 1 of 1967, yes 1967. SO, you have 365 days plus the days in 68.
The 1875 number is the SN of the trans, and has nothing to do with the Julian date.
What are the other numbers on the first line of your tag?
BTW, I've never seen a VIN derivitive stamped on a THM 400, BUT, I'm really not sure. Chuck
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Thread Starter
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi Chuck
Exactly as I write and wrote is the tag's numbering , as follows:
427
CL 68 1875
So, 427 should be the date and not the engine type ?
So this should be 427 - 365 ( for 1967 ) = the 62nd day of the year 1968, hence around the 03rd of March. Is this correct ?
CL is hydraulic lifter, OK for my L36 car .
68 is modell year 68.
1875 is S/N of the tranny.
Did SB cars in 68 come with TH350 only ?
Günther
Exactly as I write and wrote is the tag's numbering , as follows:
427
CL 68 1875
So, 427 should be the date and not the engine type ?
So this should be 427 - 365 ( for 1967 ) = the 62nd day of the year 1968, hence around the 03rd of March. Is this correct ?
CL is hydraulic lifter, OK for my L36 car .
68 is modell year 68.
1875 is S/N of the tranny.
Did SB cars in 68 come with TH350 only ?
Günther
Race Director
Joined: Apr 1999
Posts: 10,866
Likes: 717
From: Beverly Hills/Pine Ridge Florida
Originally Posted by WESCH
Hi Chuck
Exactly as I write and wrote is the tag's numbering , as follows:
427
CL 68 1875
So, 427 should be the date and not the engine type ?
So this should be 427 - 365 ( for 1967 ) = the 62nd day of the year 1968, hence around the 03rd of March. Is this correct ?
CL is hydraulic lifter, OK for my L36 car .
68 is modell year 68.
1875 is S/N of the tranny.
Did SB cars in 68 come with TH350 only ?
Günther
Exactly as I write and wrote is the tag's numbering , as follows:
427
CL 68 1875
So, 427 should be the date and not the engine type ?
So this should be 427 - 365 ( for 1967 ) = the 62nd day of the year 1968, hence around the 03rd of March. Is this correct ?
CL is hydraulic lifter, OK for my L36 car .
68 is modell year 68.
1875 is S/N of the tranny.
Did SB cars in 68 come with TH350 only ?
Günther
CL designates a hydraulic lifter BB, either 390 or 400 HP.
The 1875 is the sequential # of the trans for 68.
I have a 69 427/400 with THM 400 trans. My late 69 THM 400 has a sequential number of 2123.
My 1969 Julian date is 550, so 550-365= 185, or the 185th day of 69, which would make it roughly in June of 69.
My 69 was built in late July of 69.
I believe all small blocks in 68-9 had the THM 400, NOT the THM 350. Chuck
Last edited by Chuck Gongloff; Oct 1, 2006 at 10:54 AM.
Thread Starter
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi
looks like the automatic trannys got handled differently than the manuals.
My 68 4sped M21 close ratio actually has a stamped car VIN devirative on it, same as the engine block. Those where apparently stamped at the same time from the same guy with the same stamps together with the engine pad.
The manual tranny is a real numbers matching unit versus the auto tranny only being a correct one.
Günther
looks like the automatic trannys got handled differently than the manuals.
My 68 4sped M21 close ratio actually has a stamped car VIN devirative on it, same as the engine block. Those where apparently stamped at the same time from the same guy with the same stamps together with the engine pad.
The manual tranny is a real numbers matching unit versus the auto tranny only being a correct one.
Günther
Team Owner
Joined: Jun 2000
Posts: 38,923
Likes: 1,481
From: Southbound
Cruise-In II Veteran
Originally Posted by Chuck Gongloff
....BTW, I've never seen a VIN derivitive stamped on a THM 400, BUT, I'm really not sure...
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,923
From: Washington Michigan
Originally Posted by DZRick
JohnZ,
Were these data tags only on automatics?
Also you know a bit about Z28s don't you? If so would you mind looking at some pictures for me and let me know what you think?
Rick
Were these data tags only on automatics?
Also you know a bit about Z28s don't you? If so would you mind looking at some pictures for me and let me know what you think?
Rick
Thread Starter
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi
That's a killer now.
So, there was no system , some have the car's VIN, some not ?
Did you check if the size and fond of the tranny's VIN numbering is the same as on the engine block ?
I know that on a manual tranny, that is a must because been stamped by the same guy at the same time.
I can't see how the car's VIN could be stamped onto the THM400 tag as it is held with one central rivet and actually not sitting flat on the tranny's carcase ?
Do you have a pic of this tag with the VIN derivative ?
Rgds. Günther
That's a killer now.
So, there was no system , some have the car's VIN, some not ?
Did you check if the size and fond of the tranny's VIN numbering is the same as on the engine block ?
I know that on a manual tranny, that is a must because been stamped by the same guy at the same time.
I can't see how the car's VIN could be stamped onto the THM400 tag as it is held with one central rivet and actually not sitting flat on the tranny's carcase ?
Do you have a pic of this tag with the VIN derivative ?
Rgds. Günther
Intermediate
Joined: Nov 2005
Posts: 47
Likes: 0
From: Colorado Springs CO
Guys, I will try to post a picture later if I can get the angle under the car.
The VIN is stamped on the top side of the panledge of the THM 400 in my 71 454. It is the original transmission to the car and has the data plate and info as shown earlier by John Z.
If my memory serves me correct it is on the drivers side ledge.
Loren
The VIN is stamped on the top side of the panledge of the THM 400 in my 71 454. It is the original transmission to the car and has the data plate and info as shown earlier by John Z.
If my memory serves me correct it is on the drivers side ledge.
Loren