1970 Date Codes - General Question

[Marc K.]

Hi everyone. I'm new to this forum, but not so new to the passion we all share. Just so I can sleep better at night, please give me some feedback.

I've been slowly collecting correct part numbered accessories, and I hope date acceptable parts for my 1970. The TIM&JG states 6 months prior to body build date is okay for most dated items. Is this true for the carburetor, alternator, starter, and H2O pump specifically?

Thanks. Any insight is appreciated.
Marc

[Patrick H.]

Re: 1970 Date Codes - General Question

Most of these items are actually dated within weeks, not months of your car's build date. For example, on my June 15th 71, almost all the parts are dated the last 2 weeks of May. So, when finding replacement parts I've aimed at that same time frame rather than using the 6 month rule. The caveat is that the original water pump was built in August of 70 - 10 months prior!

The NCRS recognizes the 6 month rule, but "the closer the better" is usually true.

Patrick

[Terry M.]

Re: 1970 Date Codes - General Question

When selecting dates for components it is vital to know how the component was delivered to St. Louis -- that is was it a part that was placed on the car at St. Louis, or was it delivered as part of an assembly and then that assembly was installed on the car.

In the case of the items you mention: the carburetor, alternator, and starter were all added at St. Louis, and the advice Patrick offered is valid. However the water pump went on the engine assembly at the engine plant -- Flint, Michigan, for small blocks and Tonawanda (suburban Buffalo) New York for Mark IV engines. The date on the water pump, and all the other castings on the engine must predate the engine assembly date stamped on the passenger side front of the cylinder case. In some cases that could exceed six months from the body build date, but usually will not.

[Jack H.]

Re: 1970 Date Codes - General Question

The rule is NOT prior to body build date, it's prior to vehicle final assy date... In MOST cases, the body build date is very close to the car's final assy date, but there are sporadic exceptions (e.g. AO Smith built mid-year cars, 1969 cars with side exhaust) where there can be significant time differences between the body build date and the final assy date.

Next, some dated components on the engine were installed at St. Louis vs. coming with the engine assy from Flint/Tonawanda. Those items (see your copy of the AIM, if the part is called out in the AIM, it was probably NOT on the engine from Flint/Tonawanda) can post-date the engine's final assy date as indicated on the stamp pad.

Understanding the nature of flow regarding parts when these cars were originally built, helps to clarify the date judging process...

[Reba W.]

Re: 1970 Date Codes - General Question

Also note that glass is allowed 12 months before build.

[Alan S.]

Re: 1970 Date Codes - General Question

Hi Marc,
Rev. Mike Ernst wrote an interesting article about the date codes on his 71, for THE RESTORER , Volume 34, Number 3. While this info is for a different year than your 70, you can see the kinds of dates he found on parts on his car.
I hope you find the article useful for your car.
Regards,
Alan

[Marc K.]

Re: 1970 Date Codes - General Question

Thanks to everyone for the informative responses. I will continue to do my homework. We all know original cores are getting harder and harder to find (and expensive!), but I think the hunt is a lot of the fun.
Marc

[David P.]

Re: 1970 Date Codes - General Question

Tell me about it! Good luck in your hunt.