what is the best resource for help reading date codes.

 

Right here.

 

hi ed,
a 69 motor in a dec 69 built car, what are acceptable casting dates on the exhaust manifolds and intake? I don't have the date code available for the block, the car is in fla.
the block is an 0010 casting, mainly used in 70 and later but the vin # on the block is a match to the car. my question is, is there a date range on castings or do all dates, block heads manifold exhaust have to be the same.

 

If your asking what NCRS accepts as acceptable for judging, then its 6 months on everything. A December built small block (which is what I think you have?) would probably have a block that was built around 7-14 days before the build date of the car itself.

In reality most parts on the engine were usually within 2-4 weeks of each other on the more common cars. Some rare high performance engines had a longer date range because they didnt make many of those parts as some were unique to those engines so turnover was not as often as on common engined cars.

It would actually be VERY unusual to have all the parts the same date code.

Hope this helps,
Ed

 

So anything I can find coded for Nov 69 would be optimum

 

The letters j or k would get by? Are the 2 numbers the day and year or just the day?

 

Hi b,
For reading/decoding the dates on the numerous parts that are dated through-out the car the NCRS Technical Information Manual & Judging Guide is probably the best source of information.
In addition, through out the manual there is discussion about how close to, or far before the car's build date, the dates on parts 'typically' are.
For example:
The sb engines assembled at the Flint engine plant were often quickly shipped to St.Louis and were in cars only a few days after they had been assembled as Ed noted, An engine cast on December 31, 1970, assembled on January 7th,1971, was installed in a car assembled on January 14th 1971. Knowledgable people report that even 2-3 days was 'possible'.
Carburetor dating can be tricky because carbs were often assembled in 'batches' so there were many carbs with a certain configuration with a single date, and then maybe none for a couple of months until another batch was run.. This can affect the dates seen, especially on carbs with limited applications.
Window glass is seen on original cars with dates preceding production by more than 6 months often enough to indicate it wasn't all that uncommon.
It can all be pretty interesting if you want it to be.
Regards,
Alan

Birdcage date on a car with a Jan.14, 1971 trim tag date.


Seat cover on the same Jan. 14th car.

 

i purchased and im waiting for that book as we speak.

 

When it arrives, sit down and read through it a time or two, then keep it within handy reach. There is a considerable amount of interesting information in the Judging Guide.

 

Alan's advice, as always, will give you the most complete info. The only thing with the NCRS guide is that they will give you the 6 month rule for judging but not necessarily give you what you would typically find on an original car date wise. But then again its a GUIDE. And a very good one.

6 months is acceptable (and on a few parts I believe they give you 12 months) but most often its much closer.

For the date codes, different parts used different formats for the date code. Engine parts that were cast iron would have for example J 23 8 which would be Oct 23 1968. Starter Motors would be the same except they skipped the letter I so J would be September and M would be December. And they have it year first, month then day. Same thing with Alternators. That's where the NCRS book is critical. Carbs use a 4 digit Julian date system. You will see a number like 3638 on the carb which would be the 363th day of 1968. And it could be stamped into the carb body or maybe the base. It depends.

Also I believe things like alternators and carbs could have a date later than the engine build date as they were installed after the engine assembly date was stamped, but its unusual, but acceptable. However it must be before the trim tag date.

 

Hi just to add, the SB 010 casting was used on later 69s. I have a very original Aug 69 L46 with an 010 casting that I purchased from the original owner.

 

glass is up to one year

 

I think the side mirror also but not sure.

 

ive heard that on the glass and carbs had similar production gaps

 

Only glass as it was made in batches my the supplier

 

I was reading that the quadra jet was made in large batches so build dates had 3 month or so gaps.

 

that's the casting I have on my block, dec build

 

I knew about these stampings and numbers but never dealt with them before. I really appreciate the help and your patience, all of you, this seems to be an art all its own. fall Carlisle here I come.

 

on a 12-69 build can exhaust manifolds have a K on one cast date and a L on the other

 

Absolutely.