[Rudy427]

I have been looking at a 1968 SS 396- trim tag looks authentic with a build date 05C- 3rd week in May but engine shows a build date of 0520 after reviewing May 1968 calendar the( 05C) 3rd week ends May 18th, trying to determine what would cause these differences, would this make you suspicious.

Thanks

 

[e0em9mlc]

From what I've found:
May production for 1968
4 weeks
(A) week 1: 5 -11 May
(B) Week 2: 12- 18 May
(C) Week 3: 19-25 May
(D) Week 4: 26 May to 1 June.

So, the engine stamp in question has the engine assembled and stamped in Towanda NY on the 20th of May then shipped and installed sometime before the 25th of May... I have a 70 that was assembled in Baltimore the 3 week of Apr (19th - 25th) with an engine stamped on 02 April...But, that's a 70 model. It's possible the engine in question is authentic...It's hard to believe that someone would take time to stamp an engine and not do their homework. What is the casting date for the engine?

 

[VinceS427bb]

I have been looking at a 1968 SS 396- trim tag looks authentic with a build date 05C- 3rd week in May but engine shows a build date of 0520 after reviewing May 1968 calendar the( 05C) 3rd week ends May 18th, trying to determine what would cause these differences, would this make you suspicious.

Thanks

1968 SS 396- trim tag looks authentic with a build date 05C- 3rd week in May
this is when the tag was stamped before it was actually attached to the body
what does the engine stamp show?

 

[e0em9mlc]

Check out the below link...compare the vin with the production months...the link suggests that cars may be built later than what the vin indicates...example Cars with 04A body dates may run into week 04B of production

1968 Chevelle Production Numbers By Plant

Decoding Chevrolet VIN, trim tags, cowl tags, engine, engine block casting numbers, cylinder head casting numbers, intake manifold casting numbers, transmission, interior codes, and paint codes.

chevellestuff.net

 

[OO52]

If you're verifying a numbers matching block, it should have a matching VIN stamp under the right side cylinder head.
And while it may be theoretically possible that the engine is original, a lot of factors must be considered. Casting date is one. Remember, thats the date the block was cast, not built which could be several days after. Distance from Tonawanda is another. Shipping to a plant in California will add another 4-5 days at least.

 

[Rudy427]

From what I've found:
May production for 1968
4 weeks
(A) week 1: 5 -11 May
(B) Week 2: 12- 18 May
(C) Week 3: 19-25 May
(D) Week 4: 26 May to 1 June.

So, the engine stamp in question has the engine assembled and stamped in Towanda NY on the 20th of May then shipped and installed sometime before the 25th of May... I have a 70 that was assembled in Baltimore the 3 week of Apr (19th - 25th) with an engine stamped on 02 April...But, that's a 70 model. It's possible the engine in question is authentic...It's hard to believe that someone would take time to stamp an engine and not do their homework. What is the casting date for the engine?

Thanks for all of the replies, based your information I had found from a 1968 calendar it had indicated the first four days in May represented the first week, but what you provided makes more sense.
Thanks again- Merry Christmas and Happy New year

 

[Rudy427]

Thanks for all of the replies, based your information I had found from a 1968 calendar it had indicated the first four days in May represented the first week, but what you provided makes more sense.
Thanks again- Merry Christmas and Happy New year

Engine casting date 0520

 

[e0em9mlc]

Engine casting date 0520

0520 should be the build date mechanical stamped (with a die) on the front of the block...look at the back of the block for the date when the engine was casted at the foundry. This date should be a few months prior to the actual build date.

Mike

 

[dane63]

0520 should be the build date mechanical stamped (with a die) on the front of the block...look at the back of the block for the date when the engine was casted at the foundry. This date should be a few months prior to the actual build date.

Mike

Probably not months before, most I've seen are 2 to 3 weeks before. Of course there will always be exceptions.

 

[DaleM]

In 18 years of researching 64-72 Chevelle trim tags I've never found any true correlation between stamped week letters and actual days of a month from any plant. More often than not when one scheme may for two months, it invariably blows up the third. The camaros.org has a good description of how Camaros were built from 67-69. No, it's not Chevelle plants but it does represent both the Fisher Body plants and Chevrolet assembly plants of the time and how each side of the plant scheduled production.

As for engine assembly dates and when they were installed in the car, I've seen anywhere from a couple of days (even on the west coast) to over 3 months. Plant inventories didn't conform to a first in-first out basis. Engines, and other parts, arrived almost daily and were stacked for use. A car with a few days separation could have just had newly arrived engines spirited directly to the assembly line while older engines were still sitting in the racks. In 1968, plants were averaging anywhere from 200 to over 700 Chevelles a day (if one is to believe the released GM monthly VIN reports).

CRG Research Report - Camaro Assembly Process

First-Generation Camaro Research and Restoration Data

www.camaros.org

 

[Rudy427]

In 18 years of researching 64-72 Chevelle trim tags I've never found any true correlation between stamped week letters and actual days of a month from any plant. More often than not when one scheme may for two months, it invariably blows up the third. The camaros.org has a good description of how Camaros were built from 67-69. No, it's not Chevelle plants but it does represent both the Fisher Body plants and Chevrolet assembly plants of the time and how each side of the plant scheduled production.

As for engine assembly dates and when they were installed in the car, I've seen anywhere from a couple of days (even on the west coast) to over 3 months. Plant inventories didn't conform to a first in-first out basis. Engines, and other parts, arrived almost daily and were stacked for use. A car with a few days separation could have just had newly arrived engines spirited directly to the assembly line while older engines were still sitting in the racks. In 1968, plants were averaging anywhere from 200 to over 700 Chevelles a day (if one is to believe the released GM monthly VIN reports).

CRG Research Report - Camaro Assembly Process

First-Generation Camaro Research and Restoration Data

www.camaros.org

Great article and info- Thanks