Is this the correct dated block for my car?

[William C.]

Re: Is this the correct dated block for my car?

Not necessarily, in the era we generally get into this discussion inventory management at the engine plants tended to be "last in, first out" at least in Flint where truckloads of parts were continously trucked in from Saginaw every day. Very easy for some parts to get to the back of the pile and not be seen again until a production disruption at the foundry, or the end of the model year cleanout period where non-carryover items for the coming product were managed into as small an excess as possible. I can't speak for Tonawanda but inventory management for high volume products was not generally geared to regular stock rotation practices. Each casting number would have has it's own storage area, with no discernable effort a date co-ordination. That said, the last in-first out process typically puts the large majority of casting dates in an assembly somewhat near each other, but it was not due to a planned rotation.

[Ronald L.]

Re: Is this the correct dated block for my car?

My 2 cents on Tonawanda. Heads and intakes in the 1st to second quarter of 1966 have been shown on unmolested cars to have casting dates a day or two ahead of the TO date and only a week max two ahead of the St Louis asy date. Sure exceptions are going to arise as William points out, all that scrap we stuffed in the back to be worked off on weekend OT or especially at the end of the model year. That was July, not November, January March May or June! Yes for some reason the blocks were cast a couple months ahead, but the rest of the parts were so tight to the date they were assembled to the engines they squeaked going through the plant.

And, in my experience in the 70's from foundry to motor...a couple of days, real tight except for that occasional batch of stuff that got rejected for one reason or another.

[Charles S.]

Re: Is this the correct dated block for my car?

Chuck, Good for you. All the best in your efforts!

It appears you have a well documented car and are doing it right. If you interpret the Purpose of the NCRS, what you are doing is precisely that. From the JRM: ".....owners who have preserved or restored their Corvettes to factory original appearance and function."

Many people are here to help. I had my very first big block experience over the last few months. I learned so much from the folks right here and some close friends. It was a phenomenal learning experience.

When you progress with the project please keep us up to date...... and pictures are always fun too!

Rich

Rich, Thanks for your kind remarks. This forum has been an awesome experience. There are alot of very experienced and knowledgeable corvette folks to learn from. Getting this right is very important to me and with everyone's help who responded, I will. Take care! Chuck

[Charles S.]

Re: Is this the correct dated block for my car?

Good, you understood what I was saying!

That's why we have two judging categories: restored vs. unrestored cars. Flight judging is for restored cars and everyone knows that what's being presented is 'put together' in some form/fashion. So, let the rules work for you!!!

On your citing Noland Adams, way back when I did a statistical analysis of his Vol 2 survey data. VIN, interpolated build date versus reported key component date codes. It's been a long time, but my recollection is the MEAN interval was 5-weeks prior for those parts but the standard deviation was MIND BLOWING (something like 8-9 weeks).

Figure the typical Gaussian curve (although a Poission distribution would/should better apply) comprehends a spread of three standard deviations in either direction from the mean to capture the lion's share of a given process's typical variance and the NCRS 6-month rule starts to make REAL sense!!!

Another way to view the results of this analysis, is that while the typical time interval was 5-weeks prior, virtually all cars had one or more components that were way away from the mean...the product of lack of FIFO/LIFO inventory control and radom selection.

That says the next time you judge a car and find EACH AND EVERY dated component lines up nice and tight along the 5-week mean, there's a high likelihood that this car's dated parts have been replaced during the restoration process...

Jack, Thanks. Great points you make! I have often heard that if we were able to reach back in time and grab a 67 corvette off of the assembly line today, it would not even "Top Flight" because of the random selection of parts installed. No one cared about date codes back then. It was production and supply and demand! Thanks again. Chuck

[Charles S.]

Re: I found a block closer to my car's build date.

To all of those who responded to my question, Thank you! Just FYI, I located a 4351 block and 802 heads for my restoration. The block is dated C 31 7, and the assembly date stamped on the stamp pad is T0419IL, which should be perfect for the build date of my car, which is May 2, 67. The heads are casting number 802 and are dated D 17 7 and D 11 7. These match perfectly. I passed on the A 20 7, 4351 block. If anyone needs that block it's still for sale. Contact me and I'll direct you to the seller. Thanks to all. This was a great experience! Chuck

[Richard M.]

Re: Is this the correct dated block for my car?

Home Run!!!!! Perfect.